potency
n.the power or strength of something, like a medicine or a person's influence. It describes how effective or strong a thing is.
n.the inherent capacity or power to produce a desired effect; the strength or efficacy of a substance or argument.
“The medicine lost its potency after the expiration date.”
“Doctors were surprised by the potency of the new drug, as it required a much smaller dose than previous versions.”
“The political speech gained potency not from its volume, but from the speaker's ability to articulate the shared frustrations of the working class.”
Uncountable when referring to the general quality of strength; countable when referring to specific levels or types of power.
“A homemade brew has no standard dose, and potency varies from cactus to cactus.”
“The science has become more complicated, however, as cannabis use has become more widespread and the potency of cannabis products has increased in many parts of the world.”
Borrowed from Latin potentia. Doublet of Potenza.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.