To give away is to hand something over for free, or to reveal a secret by accident. Give away the answer, give away his old records, give away the ending.
The two senses share the idea of losing something you were holding. A dead giveaway, from the same verb, is the small sign that gives away the whole thing.
1phrasegive awayTo give something for free; also, to accidentally reveal a secret.
“Do not give away the ending to anybody who has not seen it.”
give away is a phrase.
Practised in Phrasal Verbs