Ysgyrnwg, n. a snarl, a grin
Ysgythriad, a lopping; a carving
Ysgythru, v. to lop; to carve
Ysiad, n. consuming
Ysiant, n. consumption
Ysig, a. fretting; corroding
Ysigdod, n. a contusion
Ysigo, v. to fret; to inflame
Ysigiad, n. a bruising
Yslac, a. distinct, loose, slack