Meaning of “go ahead” - Learner’s Dictionary

go ahead

phrasal verb with go uk us /ɡəʊ/ verb [ I ] (present participle going, past tense went, past participle gone)
START

B2 to start to do something:

We have permission to go ahead with the project.
PERMISSION

B2 something that you say to someone to give them permission to do something:

''Can I borrow your book?'' ''Yes, go ahead.''
go-ahead noun

get/give the go-ahead

(Definition of “go ahead” from the Cambridge Learner’s Dictionary © Cambridge University Press)