סָאַב [to be rough, ugly,] to be filthy, unclean, repulsive.
Pi. - סִיאֵב to soil, make unclean; to unfit for sacrifice on account of repulsive appearance. Part. pass. מְסוֹאָב, f. מְסוֹאֶבֶת; hands.Ḥall pl. מְסוֹאָבִים, מְסוֹאָבִין; מְסוֹאָבוֹת.—ידים מס׳ unwashed hands. Ḥall. II, 2. Ḥull. II, 5; a. fr.—Tem. 8ᵃ ירעו … הא מס׳ וקיימין (you say) ‘let them go to pasture until they become unfit for sacrifice’, but are they not already unfit (being blemished)?
Hithpa. - הִסְתָּאֵב to become filthy, repulsive, unfit for sacrifice. Yeb. XI, 5 יהא רועה עד שיִסְתָּאֵב let it go to pasture, until it becomes unfit for sacrifice. Tem. l. c. עד שיִסְתָּאֲבוּ, v. supra. Ib. IV, 1 עד שתִּסְתָּאֵב; a. fr.