Green’s Dictionary of Slang

1. close, friendly.

a.1955		‘Good-Doing Wheeler’ in D. Wepman et al. Life (1976) 75: No one could know how things would go / For once he had her up tight.
1968		J. Colebrook Cross of Lassitude 53: The sort of high-class broad who, if you had her ‘up tight’, would not only make you rich but would make you happy as well.
1970		R.D. Abrahams Positively Black 122: This emphasis on knowing a large number of people does not mean that fidelity in friendships is not valued. Indeed being ‘up tight’ with someone, having him as an ‘ace boon coon,’ is a state which is much admired.
1980		E. Folb Runnin’ Down Some Lines 259: uptight […] 5. Intimate.

2. (US campus) very attractive.

1966

Current Sl. I:1 5/1: Uptight Very attractive, particularly when accompanied by a sunny personality.

3. satisfactory, good.

1968		‘Hy Lit’ Hy Lit’s Unbelievable Dict. of Hip Words 2: When using hi baby in a greeting, it means everything is uptight, friendly, and you are together.
1969		B. Beckham My Main Mother 60: ‘Beautiful,’ said Julius. ‘Uptight, beautiful.’ [Ibid.] 126: Don’t worry [...] Julius has got things uptight.
1972		G.S. Holt ‘Inversion in Black Communication’ in Kochman Rappin’ and Stylin’ Out 159: Blacks use ‘double meaning’ as a verbal device to deceive whites [...] ‘Uptight’ may mean either ‘beautiful, together, happy, favorable,’ etc., or ‘tense, afraid, angry, unfavorable’.
1980		E. Folb Runnin’ Down Some Lines 180: Everythang will be all right, uptight and outasight.

4. having sexual intercourse.

1967–8		Baker et al. CUSS 217: Uptight Sexually aroused.
1980		E. Folb Runnin’ Down Some Lines 153: Other expressions for intercourse – [...] to be uptight (in the sense of up tight against another’s body).