late 14c., "refraining from undue indulgence," especially in reference to food and drink, from Old French abstinent (earlier astenant) "moderate, abstemious, modest," from Latin abstinentem (nominative abstinens) "temperate, moderate," present participle of abstinere, abstenere "withhold, keep back, keep off," from assimilated form of ab "off, away from" (see ab-) + tenere "to hold" (from PIE root *ten- "to stretch").