holla at (one)

1. slang To communicate or make contact with one. A colloquial pronunciation and spelling of "holler." Be sure to holla at my cousin Cheryl when you're in Brooklyn.

2. slang Flirt with or hit on one, especially a woman. If I ever see you holla at my girl like that again, I will end you.

3. slang Used to make a salute or expression of respect to one, as on radio, television, or the Internet; to shout out to one. I'll be sure to holla at ya when I'm on the talk show next week.