Sytholdeb, n. stiffening tendency
Sythu, v. to stiffen; to make or become erect
Syw, a regular, trim, smart
Sywed, n. astronomy
Sywedydd, n. astronomer
Sywedyddol, a. astronomical
Sywidŵ, n. the titmouse
Sywino, v. to turn or use continually; to dissipate
Sywio, v. to make uniform, to put in trim
Sywydd, n. star knowledge