Word: giveaway
Something that is given away or handed out for free. Example: The T-shirt was a giveaway from the company that sells the software.
An event at which things are given away for free.
Something that is obvious or apparent; something that reveals a secret. Example: The frosting in his beard was a giveaway that he had been munching the cake.
You can find a list of possible crossword clues for GIVEAWAY below.