Consent
Etymology
From Latin “consentire,” “to feel together, agree,” from “com,” “together,” + “sentire,” “to feel.” Consent is literally a feeling-with — an alignment of will — which is why coerced or uninformed agreement, where no real meeting of feeling occurs, fails to count.
noun · /kun-SENT/
Voluntary agreement to something that affects you, given freely and with understanding of what you are agreeing to.
What it names
Use it when the whole legitimacy of an act — medical, sexual, contractual, political — turns on whether the affected person genuinely said yes.
Example
The study could not begin until every participant had given informed consent.
Related idea
Consent (con-, “together”) and dissent (dis-, “apart”) are built from the same Latin root “sentire,” “to feel” — to agree is to feel with, to dissent is to feel apart. Note too that mere compliance is not consent: obeying under threat is agreement in form only.