tooth

tooth — 名詞

1. a white or off-white part fixed in a row inside your mouth, made of a hard, bone

1.名詞A1
釋義

牙齒

用於咀嚼和咬碎食物的口腔硬組織

a white or off-white part fixed in a row inside your mouth, made of a hard, bone-like material, used to bite and break food into small pieces before you swallow it.

例句

The dentist told Trang to brush her teeth at least twice every day.

牙醫告訴 Trang 她需要每天至少刷兩次牙齒。

collocation: brush teeth

Valentina's baby cried all night because a new tooth was pushing through her gum.

Valentina 的寶寶哭了一整夜，因為新牙正在從牙齦中長出來。

infant tooth growth

用法筆記

Teeth are counted individually — you say 'I have a loose tooth' (singular) or 'I brush my teeth' (plural). The first set of teeth in children are called baby teeth or milk teeth; these fall out and are replaced by permanent teeth or adult teeth. Common dental verbs include 'brush', 'floss', 'fill', 'extract', and 'pull'.

常見錯誤

❌I have a tooth decay.
✅I have tooth decay.
💡'tooth decay' is an uncountable noun; do not use 'a'.
❌My teeth is hurting.
✅My teeth are hurting.
💡'teeth' is the plural form and takes a plural verb.
❌I need to go to dentist for my tooth.
✅I need to go to the dentist for my tooth.
💡use the definite article with 'dentist'.

2. one of a set of small, pointed pieces that stick outward from the surface of cer

2.名詞B1
釋義

齒狀物

工具邊緣的尖銳突出部分

one of a set of small, pointed pieces that stick outward from the surface of certain tools and are designed to help cut, grip, or hold material — found on items like saws, combs, gears, and zippers.

例句

The saw's teeth were so dull that Tuan could not cut through the wooden board.

鋸子的齒狀物已經變鈍了，Tuan 無法切穿那塊木板。

Ryan ran a comb through his wet hair, and one of the teeth snapped off.

Ryan 用梳子梳理濕頭髮時，梳子的一個齒狀物斷掉了。

同義詞
  • cog

    specifically one tooth on a gear wheel

  • tine

    a prong of a fork or rake, similar but not interchangeable

  • prong

    a pointed projection, usually on a fork or electrical plug

文法句型

the teeth of a [tool]

[tool] + tooth / teeth

用法筆記

This sense is most common in compound nouns and fixed expressions: 'fine-toothed comb', 'sawtooth', 'gear tooth', and 'toothed wheel'. The singular form (e.g., 'one tooth on the gear is broken') is used when referring to a single projection.

常見錯誤

❌The comb's tooths are broken.
✅The comb's teeth are broken.
💡the plural is always 'teeth', never 'tooths'.
❌I need a fine-tooth comb.
✅I need a fine-toothed comb.
💡the adjective form is 'fine-toothed'.

3. the ability of a law, rule, committee, or other authority to be taken seriously

3.名詞B2
釋義

效力

法規或組織發揮強制作用的能力

the ability of a law, rule, committee, or other authority to be taken seriously and to force people to obey or comply, usually because it has real punishment or enforcement power.

例句

The new regulations give the environmental agency real teeth to punish polluters.

新法規賦予環保機構真正的效力來懲罰污染企業。

pattern: give [something] teeth

Without an inspection system, the safety rules have no teeth and companies ignore them.

如果沒有檢查制度，這些安全規定就沒有效力，企業也不會理會。

同義詞
  • enforcement power

    more explicit, used in formal/legal contexts

  • authority

    broader in meaning; includes legal right, not just the power to enforce

  • bite

    informal synonym, e.g., 'the new rules have bite'

文法句型

give [noun] teeth

[noun] has / lacks teeth

[noun] with teeth

用法筆記

Almost always used in specific phrases such as 'give teeth to', 'have teeth', 'lack teeth', or 'with teeth'. The subject is usually an abstract entity — a law, regulation, policy, committee, sanction, or agreement. Never used in the singular ('a tooth') with this figurative meaning. This sense is most common in news, political, and legal writing.

常見錯誤

❌The law has a tooth now.
✅The law has teeth now.
💡always use the plural 'teeth' for this figurative meaning.
❌The tooth of the law is weak.
✅The law lacks teeth.
💡use the standard fixed expression rather than an unusual singular form.