IPA: //sʌbˈpoʊtənt//
KK: /sʌbˈpoʊtənt/
Having less strength or effectiveness than usual.
The medication was subpotent, leading to insufficient relief from symptoms.
Subpotent → It is formed from "sub-" (meaning under) and "potent" (from Latin "potens", meaning powerful or having power). The word describes something that is less powerful or having less potency than something else.
Think of something that is 'under' ('sub-') in power or effectiveness — that's why subpotent means having less power.