Meaning of “plough sth back” - Learner’s Dictionary

plough sth back

phrasal verb with plough UK (US plow) uk us /plaʊ/ verb [ I, T ]

to spend the money that a business has earned on improving that business:

All profits are ploughed back into the company.

(Definition of “plough sth back” from the Cambridge Learner’s Dictionary © Cambridge University Press)