Meaning of “spring sth on sb” - Learner’s Dictionary

spring sth on sb

phrasal verb with spring uk us /sprɪŋ/ verb (past tense and past participle sprang, also US sprung, past participle sprung)

to suddenly tell or ask someone something when they do not expect it:

I'm sorry to spring this on you, but could you give a talk at tomorrow's meeting?

(Definition of “spring sth on sb” from the Cambridge Learner’s Dictionary © Cambridge University Press)