{adj. phr.}, {informal} Unpleasant or bad but to be expected; not harder than usual; not unusual. * /Keeping ants away from a picnic lunch is all in the day's work./ * /When the car had a flat tire, Father said that it was all in a day's work./ Compare: PAR FOR THE COURSE, PUT UP WITH.
ALL IN THE DAY'S WORK
Meaning of ALL IN THE DAY'S WORK in English
Slang English vocab. Английский сленговый словарь. 2012