Green’s Dictionary of Slang

1. very pretty, extremely attractive.

1968		H. Sebold Adolescence 250: Foxes are the good-looking, dyno, out-of-sight chicks.
1989		P. Munro Sl. U. 75: That chick is dyno.

2. excellent, first-rate.

1989		P. Munro Sl. U. 75: Marcie, that dinner you made was way dyno.
2020		G. Armstrong Young Team 133: A’m ravin [...] n it feels dyno.