effectiveness; capacity or power to produce a desired effect
The vaccine's efficacy was proven through rigorous clinical trials over several years.
Vocabulary like efficacy appears on the Digital SAT in Words-in-Context questions, where you choose the word that fits a passage's meaning and tone. You can also drill this word with vocabulary flashcards.
misrepresentation; a fraudulent or duplicitous representation
length; the period of time during which something continues
lessen; become smaller or lose substance
flow back, flow out; flow back or recede
enthusiastic; joyously unrestrained
drawn from many different sources; selecting what seems best of various styles or ideas
cover; one celestial body obscures another
enthusiasm; the process of bubbling as gas escapes