Meaning of “go on sth” - Learner’s Dictionary

go on sth

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

to use a piece of information to help you discover or understand something:

Her first name was all we had to go on.

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