half-life
B1CEFR level
30/100Rarity: fairly common
TechnicalRegister
The time taken for a drug’s concentration to fall by half.
Its short half-life means dosing three times a day.
Rarity runs from 0 (a word everyone knows) to 100 (almost never seen outside specialist or literary writing). Level is the word's real difficulty on the CEFR scale, from A1 to C2.
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