1
general::
Phrase(s): wear something off (of) something [and] wear something off
to grind or rub something off something. (Of is usually retained before pronouns.) • The grinding of the bottom of the boat on the sandbanks wore the barnacles off the hull. • The sand wore off the barnacles., Phrase(s): wear off ((of) something)
[for something] to be ground or rubbed away. (Of is usually retained before pronouns.) • The paint has worn off the porch steps. • The finish is wearing off., Phrase(s): wear off
[for the effects of something] to become less; to stop gradually. • The effects of the painkiller wore off and my tooth began to hurt. • I was annoyed at first, but my anger wore off.
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Diminish gradually, lose effectiveness, as in We'll wait till the drug wears off. [Late 1600s]
American Heritage Idioms