Green’s Dictionary of Slang

in direct confrontation.

1980		E. Folb Runnin’ Down Some Lines.
1983		R. Klein Jailhouse Jargon and Street Sl. [unpub. ms.].
1993		K. Scott Monster (1994) 149: Everyone wanted to rat-pack him, but Monk insisted on it being head up.
2000		P. Beatty Tuff 37: Seeing a strong black woman such as yourself going head-up with the bullshit makes me wonder what I can do to straighten my game out.