Probably of foreign origin; Kisleu, the 9th Heb. Month -- Chisleu.
H3691. Kislev
כִּסְלֵו proper name [masculine] kislew, ninth month (post-exilic) = November-December, Zechariah 7:1; כ ׳בְּחֹדֶשׁ Nehemiah 1:1 (ᵑ7 id.; loan-word from Babylonian kislimu, kislivu, Muss-ArnJBL 1892, 167; conjectures on etymology by JenZA ii, 210, Anm. 3 Hptib. 265, Anm. 2; Palmyrene כסלול VogNo. 24; Greek χασελευ I Makk Nehemiah 1:54).