Although the derivation of the word itself is pretty revolting and definitely derogatory (from spastic), the noun can be used both in an offensive way and an affectionate way. On the one hand, it can be used as a put down when calling another person a stupid idiotic fool but also between friends, when one acts a bit silly.

The verb, to spaz (or to be spazzed out!) means lapsing into a state of sleepy/day-dreamy stupor. For example, “Sitting here, in this hot sunshine, is really spazzing me out!”

spaz or spazz (slang)

One who is considered clumsy or inept.

[Origin: 1960–65; shortening and alter. of spastic]