adv.
Pronunciation: ' w ə n(t)s
Function: adverb
Etymology: Middle English ones, from genitive of on one
Date: 12th century
1 : one time and no more <rode a horse only once >
2 : at any one time : under any circumstances : EVER <didn't once thank me>
3 : at some indefinite time in the past : FORMERLY <was once a booming mining town>
4 : by one degree of relationship <first cousin once removed>
– once and for all
1 : with finality : DEFINITIVELY
2 : for the last time
– once in a while : NOW AND THEN