Green’s Dictionary of Slang

1. to have adventurous sex; to have anal intercourse.

[1787		‘Hush Cat from under the Table’ in A. Carpenter Verse in Eng. in 18C Ireland (1998) 402: You jolly young rake who loves for to freak / To sport and play with girls so pretty].
1969		‘Iceberg Slim’ Pimp 58: I was freaking for free.
1979		Lady B ‘To the Beat, Y’all’ 🎵 I say, you bring the butter and I’ll bring the salt / And if you don’t freak then it ain’t my fault.
1985		T.R. Houser Central Sl. 23: freak, to To have anal intercourse. ‘I do anything for money honey, but I don’t be freakin’.’.
1999		‘Master Pimp’ Pimp’s Rap 52: We must have been freaking for at least 25 minutes. I hadn’t stuck it in yet.
2003		G. Tate Midnight Lightning 85: One of his fetishes was young boys. He would set up these lavish parties so that everybody could just freak together. Weird things used to occur.

2. (US campus, also freak all over, freak on) to dance in a highly sexual manner, to simulate sex on the dance-floor.

1989		P. Munro Sl. U. 83: freak [...] 3. to dance very seductively [...] freak on/freak all over to dance very seductively with.
1997–2002		Hope College ‘Dict. of New Terms’ 🌐 freak v. tr. To dance in close proximity with a member of the opposite sex [...] ‘That guy over there just came over and started freaking me.’.
2008		‘Grandmaster Flash’ Adventures 6: Family and friends, grinding and freaking, moving and grooving. Every one of 'em in step with the beat.
2015		P. Beatty Sellout (2016) 135: Grinding her pelvic bone rhythmically against his backside and playing with his ears. ‘Freaking,’ we used to call it, and she pranced around [...] caressing the beat.

3. to have sexual intercourse.

1994		N. McCall Makes Me Wanna Holler (1995) 341: We gonna freak this skank when her head gets bad.
2002		Teen Lingo: The Source for Youth Ministry 🌐 freak [...] 3. v. to copulate.
2004		T.I. ‘Let’s Get Away’ 🎵 [Girl] Hey, let’s get a room, shawty we can freak somethin’ if you down.

4. to excite (sexually).

2005

posting at advicechick.com 8 Nov. 🌐 How do I freak a married man so good that it makes him leave his wife for me?

5. (US drugs) to disguise a marijuana cigarette by wrapping it in a ‘legitimate’ cigar wrapper.

2008

G. Pelecanos Way Home (2009) 145: A joint of weed he had freaked in a Black and Mild wrapper.