{adj. phr.} Busily doing something; active. * /His rule for success was to keep always at it./ * /The couple who owned the little cleaning shop were at it early and late./ * /Mr. Curtis heard a loud crash in the next apartment - the neighbors were at it again./
AT IT
Meaning of AT IT in English
Slang English vocab. Английский сленговый словарь. 2012