From kara'; the leg (from the knee to the ankle) of men or locusts (only in the dual) -- leg.
see HEBREW kara'
H3767. kera
[כֶּ֫רַע] noun [feminine] leg, (Late Hebrew כֶּרַע, Aramaic כַּרְעָא, — only dual feminine כְּרָעַיִם Leviticus 11:21 3t.; כְּרָעָ֑יִם 9:14; sf כְּרָעָיו Exodus 12:9 3t.; — two (bending) legs, of animals in ritual phrase of P, עַלכְּֿרָעָיו ראֹשׁוֺ 12:9 his head with his legs, Leviticus 4:11; (יוׅ ו(ה)כרע (ה)קרב(ו) (his) inwards and (his) legs Exodus 29:17; Leviticus 1:9, 13; 8:21; 9:14; Amos 3:12 (of legs of lamb in mouth of lion); of the long bending hinder legs of the Saltatorial Orthoptera (see TristrNat. Hist. Bib. 309; DrJoel 84) Leviticus 11:21 הָאָרֶץ עַל בָּהֵן לְנַתֵּר לְרַגְלָיו מִמַּעַל כְרָעַיִם לוֺ אשׁר which have bending legs above their feet, etc.