Other forms: refrained, refrains, refraining
To refrain is to hold yourself back from doing something. Refrain from smoking, please refrain, refrain from comment.
The preposition is from and the construction takes an -ing form: refrain from asking. Please refrain from is the standard polite prohibition on signs and announcements, and it is more formal than do not. There is a separate noun refrain meaning the repeated part of a song or poem, which is an entirely different word. Note that the two refrains are unrelated and have coexisted in English for six hundred years.
1verbrefrainTo hold yourself back from doing something.
“Please refrain from using your phone during the performance.”
synonyms: abstain, hold back
2nounrepeatedThe repeated part of a song or poem.
“Everyone joined in the refrain of the old folk song.”
refrain is a holding back, or a repeated part.
Also accepted in games: abstain
Latin refrenare means to bridle, from frenum, a bridle — holding a horse back. The musical refrain comes from a different Latin word about breaking, which is why the two are unconnected.
Proto-Indo-European
*bʰreg-
Latin
refrēnāre
Old French
refrener
Anglo-Norman
refrener
Middle English
refreynen
English, today
refrain
Middle English refreynen, from Anglo-Norman refrener, Old French refrener, from Latin refrēnāre, from re- + frēnāre, from frēnum.
Etymology from Wiktionary, CC BY-SA
Practised in Sharper Verbs