{v. phr.} 1. To become less active; grow lazy. * /Since construction work has been slacking off toward the end of the summer, many workers were dismissed./ 2. To gradually reduce; taper off. * /The snowstorms tend to slack off over the Great Lakes by the first of April./
SLACK OFF
Meaning of SLACK OFF in English
Slang English vocab. Английский сленговый словарь. 2012