Green’s Dictionary of Slang

1. (US black) very well dressed.

a.1954		‘Mexicana Rose’ in D. Wepman et al. Life (1976) 37: My man Smitty was also pressed / And looked real tough. I must confess.
1959		‘Hal Ellson’ Jailbait Street (1963) 8: I’m all pressed. I’m not ruining my clothes.
a.1962		‘Duriella du Fontaine’ in D. Wepman et al. Life (1976) 45: I was also pressed in some of the best, / But I couldn’t compare with Van.
1971		H.E. Roberts Third Ear n.p.: pressed adj. to be very well dressed.
1980		E. Folb Runnin’ Down Some Lines 111: There is even a larger vocabulary that refers to being well dressed ([...] pressed, dressed tight, dressed down, dapped down, choked down).
1981		Maledicta V:1+2 (Summer + Winter) 268: A well-dressed man is clean or pressed to the max.

2. (US black) used of hair that has been chemically straightened.

1980

E. Folb Runnin’ Down Some Lines 141: It was still not uncommon to hear teenagers talking about getting their hair conked, fried, pressed, or gassed.