My spell-check is saying prismic isn’t a word. Looked it up, and sure enough, it doesn’t appear to be a word. Why not?
What is the adjective meaning prism-like? Is it just “prism-like”?
You’re looking for “prismatic.”
Prismatic.
prismatic?
far out…that was pretty damn fast!
Speed of light, man. 
Prismolicious
Prismiffic?
Prizzymizzy
In light of the full spectrum of answers illuminated here, I must refract my previous post.
In all seriousness, “prismy” is a real word.
Ah, the English language. Always good for a ‘WTF? Seriously?!’
I work in a prism, with many refractory patients…
It is actually a word through the concept of “common and accepted usage.” When a new word is introduced into the common lexicon it becomes real by de facto. A good example is the word “conversate” or “fuckin’ A”. These are now common and accepted “words”.
The OED cites “prismic” as an alternative spelling for prismatic:
Priapism?
Prizizzle?
That’s fine, but I don’t think that “prismic” falls under “common and accepted usage.” I don’t believe I had ever heard of it before this thread.
RR
Prismic
This post was prismized by the prismist!
It’s funny, as soon as I read the word “prismatic,” “prismic” immediately seemed awkward and flat-out wrong. Just a total brain fart.