Definition of "yce"

If thou doſt marry, Ile giue thee / This plague to thy dowry: / Be thou as chaſte as yce, as pure as ſnowe, / Thou ſhalt not ſcape calumny, to a Nunnery goe.]

(First Quarto), London: […] [Valentine Simmes] for N[icholas] L[ing] and Iohn Trundell, published 1603, [Act III, scene i]