present participle. Sweet holy monkey balls! That's gross.
Real citation: "I'd rather see Lindsay do the nasty with Coulson. Which would still be ewwwww-inspiring, but not so much."
(KMS, Jan. 19, 2004, http://groups.google.com/group/rec.arts.tv.soaps.abc/
Made-up citation: "As the Bible says, 'Blessed is the man who doesn't walk in the counsel of the ewwwww-inspiring, nor stand in the way of sinners, nor sit in the poo-poo of farmboys."