"Hawkish" eh?

"Hawkish", why do we still use that antiquated word, and only ever in the context of interest rates.
I know what it means, but for some reason, it's also a valid way of saying that something "has a physical appearance reminiscent of a hawk".
But isn't that valid with all words, so anything can be blankish. Yet nobody says retangleish, or oblongular for that matter.