What does "freebie" mean?

Something which is free; a giveaway or handout.

Freebie

Common synonyms include: bonus, buckshee, charitable, complimentariness, complimentary, complimentary item.

/ˈfɹiːbi/ noun, slang

noun, slang ·Moderate ·High school level

Noun

1
Something which is free; a giveaway or handout. informal
"I didn't buy a thing, but they were handing out some neat freebies and samples."
2
something that is free (usually provided as part of a promotional scheme) wordnet

"This planner is a freebie from the bank."

From free + -b- (epenthetic) + -ie or free + -bie.