root
root — noun
1. the portion of a plant found beneath the earth's surface, which draws moisture a
the portion of a plant found beneath the earth's surface, which draws moisture and nutrients from the surrounding soil while keeping the plant upright and stable.
The oak tree's roots spread wide under the garden soil.
collocation: spread wide / deep roots
Ramón carefully dug around the carrot to avoid cutting the root.
concrete action: dig around to avoid cutting
These plants have shallow roots, so they need watering every day.
When a tree falls in a storm, the roots are often pulled out of the ground.
用法筆記
Often appears in the plural form roots when referring to the whole underground system of a plant.
2. the main reason that a bad situation or problem exists; the thing from which som
the main reason that a bad situation or problem exists; the thing from which something unpleasant grows.
Lack of sleep is often the root of many health problems.
the root of + problem / issue
The police are trying to get to the root of the corruption scandal.
get to the root of something
Christopher believes that poverty is at the root of most social conflicts.
The committee traced the root of the financial crisis back to poor lending practices.
用法筆記
Common in fixed phrases like 'root cause', 'the root of the problem', and 'get to the root of something'. Unlike sense 3 (ORIGINS), this sense has a negative connotation — the thing being described is undesirable.
常見錯誤
3. a person's family, cultural, or geographic background; the place or community th
a person's family, cultural, or geographic background; the place or community that a person or thing comes from originally.
Padma decided to return to her roots in southern India after twenty years abroad.
return to one's roots
The music festival celebrates the Celtic roots of the region's folk traditions.
cultural / ethnic roots
Yael's family has deep roots in the farming community of the valley.
Many traditional dishes have their roots in home cooking rather than restaurant kitchens.
- heritage
traditions and values passed down; broader and more abstract than roots
- background
the kind of family and experience someone has; less emotional
- ancestry
specifically about family lines going back generations
用法筆記
Almost always used in the plural (roots). The emphasis is on connection to a place, culture, or tradition — different from sense 2 (ROOT CAUSE), which focuses on negative causation.
4. the section of a tooth, hair strand, or fingernail that sits beneath the skin su
the section of a tooth, hair strand, or fingernail that sits beneath the skin surface or gum, holding it firmly in place.
The dentist said the infection had reached the root of my molar.
tooth root / root of a tooth
Zuri noticed a grey hair growing from the root near her temple.
hair root / grows from the root
Damage to the nail root can make the fingernail grow back with an odd shape.
The dentist used an X-ray to check whether the root of the cracked tooth was still healthy.
用法筆記
Often used in compound nouns: tooth root, hair root, nail root. The root is the living part that produces new growth (for hair/nails) or anchors the structure (for teeth).
5. the smallest meaningful unit in a language, to which prefixes and suffixes may b
the smallest meaningful unit in a language, to which prefixes and suffixes may be attached to build related vocabulary.
The Latin root 'scrib' means 'to write' and appears in 'describe' and 'inscribe'.
Latin / Greek root + examples
Quan looked up the root of 'photograph' and found it comes from Greek words for 'light' and 'writing'.
root of a word / comes from
Takeshi recognised the Greek root 'bio' in 'biodegradable' and guessed it meant 'life'.
The word 'biology' has the Greek root 'bios', which means 'life'.
- affix
a prefix or suffix added to a root
用法筆記
In linguistics, a root differs from a stem or base — the root is the smallest meaningful part. But in everyday learning, 'root' is used more loosely to mean any core word from which related words are formed.
6. a value that makes a mathematical equation true when it is put in place of the u
a value that makes a mathematical equation true when it is put in place of the unknown variable.
The quadratic equation x² − 9 = 0 has two roots, which are the numbers 3 and −3.
has two roots (equation solving)
Sumin solved the quadratic and found the roots were real numbers.
real roots / complex roots
For her algebra test, Anong solved x³ − 8 = 0 and found that 2 was a real root.
Noa solved for the roots of the polynomial and found both were positive integers.
用法筆記
Distinct from sense 7 (SQUARE ROOT). In this sense, 'root' means any solution to an equation — not limited to square roots. For example, the roots of x − 5 = 0 is just 5.
7. a value that serves as a factor in repeated self-multiplication a set count of t
a value that serves as a factor in repeated self-multiplication a set count of times to arrive at a particular result — the square root of 16 is 4, since 4 × 4 = 16.
The square root of 64 is 8, because multiplying 8 by itself gives the total of 64.
square root of [number]
Élise used a calculator to find the cube root of 27.
cube root / square root
For her math homework, Ayana calculated the square root of 144 and got 12.
The cube root of 125 is 5, because multiplying 5 by itself three times gives 125.
用法筆記
Distinguish from sense 6 (EQUATION SOLUTION). Sense 7 is specifically about roots of numbers (e.g. square root, cube root), while sense 6 is about roots of equations. In math notation, a square root is shown with the √ symbol.
8. the pitch at the bottom of a chord, which determines the chord's name and its ov
the pitch at the bottom of a chord, which determines the chord's name and its overall harmonic quality.
In a C major chord, the note C is the root of the chord.
root of the chord
Rania learned to identify the root note by listening to the lowest pitch in a chord.
root note
Ezra played the C major chord on his guitar, then moved the root to E and heard a different chord.
In a G major chord, the note G serves as the root and the chord is built up from there.
- tonic
often confused; tonic is the first note of a scale, while root is the base of a chord
- fundamental
in acoustics, the lowest frequency of a sound; related but not identical
用法筆記
Used mainly in music theory. In a chord, the other notes (third, fifth, seventh) are described in relation to the root.
root — verb
1. to search for something by moving things around or turning them over, often in a
to search for something by moving things around or turning them over, often in a rough or careless way.
Noa rooted through the drawer looking for a pair of scissors.
root through + noun phrase
The pig was rooting around in the mud with its snout.
root around
Lotte rooted in her backpack for the train ticket while the queue moved forward.
Lotte rooted around in the toolbox until she found the right screwdriver.
文法句型
root + through/around + noun phrase
用法筆記
Almost always used with a particle like through, around, or in. The object being searched through is usually a messy container or area (drawer, bag, pile, soil).
常見錯誤
2. of a plant or cutting: to send out roots and start establishing itself in soil o
of a plant or cutting: to send out roots and start establishing itself in soil or another growing material.
The rose cuttings took about three weeks to root in the potting mix.
to root in [growing medium]
Eve placed the stem in water until it rooted, then planted it in a pot.
Mrs. Chen placed her jasmine cuttings in a jar of water on the windowsill, hoping they would root.
The gardener showed us how to root lavender cuttings in small pots of sand.
用法筆記
This verb is often used in gardening contexts. The related phrasal verb 'take root' is more common in everyday speech for the same idea. The transitive form (root a cutting) is also used by gardeners.