occasionally ***
on occasion
once in a while
now and then
now and again
at times **
from time to time

On occasion, they happened to be in the wrong place.

He has also played in the half forward line on occasion.

The church is used on occasion for special services, including one summer service each year.

But all good things must come to an end, on occasion.

These became a place where father and son came together on occasion.

But on each occasion he had company, and I needed him alone.

A lot of them died, and I almost did on more than one occasion.

He could have killed all of us on more than one occasion.

But on one occasion he got them all at once.

I've done the same sort of thing on more than one occasion.