I'd use any of these words in a heartbeat if only to jargogle whomever I was with.
20 Obsolete English Words that Should Make a Comeback
I use freck all the time but am apparently "off definition".
Other terrific words: Deliciate, Malagrugrous, and Ludibrious. The first ten are terrific, the second ten not so much. Still read the whole thing. As a former professional writer and a gal with a BA in Medieval English Lit., I love this clobber.