dosage

Compared meaning: the amount of medicine to take (noun).

比较义项：药物的剂量（名词）。

• dose

  Refers to a single measured amount of medicine actually taken or given at one time; countable ('a dose', 'two doses'); also used loosely for non-medical amounts, like radiation.

  指某一次实际服用或给予的一份测量好的药量；可数（如“一剂”“两剂”）；也可宽泛地用于非药物场合，如辐射剂量。

  She forgot to take her evening dose of the medicine.

  她忘了服用晚上那一剂药。

• dosage 本词

  Refers to the prescribed amount or rate of a medicine, as a standard or instruction rather than one specific act of taking it; usually uncountable, common in medical instructions and labels.

  指药物规定的用量或服用标准，是一种说明或规范，而不是某一次具体的服用行为；通常不可数，常见于医嘱和药品说明中。

  The label warns not to exceed the recommended dosage.

  标签上警告不要超过推荐的剂量。

Both words describe how much medicine to take. Dose is a single measured amount taken at one time, countable ('a dose', 'two doses'), and can also mean a non-medical amount, like radiation. Dosage is the prescribed amount or rate, usually uncountable, common on medical labels.

这两个词都指“该服用多少药”，但 dose 侧重某一次实际服用或给予的一份药量，可数，也可以指非药物的一次性作用量；dosage 侧重按规定应服用的剂量或用量标准，常出现在说明书、处方等正式语境中，通常不与数词连用。