1. To work in an irregular or intermittent manner, with periods of work alternating with periods of not working or doing other activities
She has been working on and off as a freelance consultant for the past five years.
Ela tem trabalhado de forma intermitente como consultora freelancer nos últimos cinco anos.
2. To continue working on something sporadically, not consistently or continuously
He works on and off on his novel whenever he finds time.
Ele trabalha esporadicamente em seu romance sempre que encontra tempo.