1. verb To give one secret, private, or insider information or news, especially that which gives them or someone else an advantage of some kind. A noun or pronoun can be used between "tip" and "off." An anonymous source tipped off reporters that the senator had been using campaign money to fund private trips to the Bahamas. I tipped the cops off about the gang's plan to rob the bank.

2. noun The act of giving one secret, private, or insider information or news, especially that which gives them or someone else an advantage of some kind. As a noun, it is usually hyphenated. Thanks to an anonymous tip-off, police were able to blow the lid off the smuggling ring.

3. noun The start of a basketball game, which is begun with a jump ball ("the tip"). As a noun, the phrase is usually hyphenated. Yeah, I'd love to watch the game. What time is tip-off?

4. noun By extension, the start of some event. As a noun, the phrase is usually hyphenated. The convention runs all weekend. Tip-off is on Friday at 4.