on and off
(also off and on) for short periods but not regularly over a long period of time

[TahlilGaran] Dictionary of Contemporary English ▲

on and off
intermittently, now and then
It has been raining on and off since early this morning.

[TahlilGaran] English Idioms Dictionary ▲

on and off
See: OFF AND ON.
{adv.} Not regularly; occasionally; sometimes.
Joan wrote to a pen pal in England off and on for several years.

It rained off and on all day.
- Sometimes used with hyphens like an adjective.
A worn-out cord may make a hearing aid work in an off-and-on way.
Compare: BY FITS AND STARTS, FROM TIME TO TIME, NOW AND THEN.

[TahlilGaran] English Idioms Dictionary ▲