[adverb] [formal] - continuing on from a particular point in time, esp. after something else has stopped happeningFor the first month you will be working in teams of four, but thereafter you will be working in pairs.He left the priesthood in 1970 and settled in the Washington area shortly thereafter (= soon after that).
THEREAFTER
Meaning of THEREAFTER in English
Cambridge English vocab. Кембриджский английский словарь. 2012