{adv. phr.} At fairly regular intervals; fairly often; repeatedly. * /John comes to visit me every now and then./ * /It was hot work, but every so often Susan would bring us something cold to drink./ Compare: NOW AND THEN.
EVERY ONCE IN A WHILE
Meaning of EVERY ONCE IN A WHILE in English
Slang English vocab. Английский сленговый словарь. 2012