From caphach; something (spontaneously) falling off, i.e. A self-sown crop; figuratively, a freshet -- (such) things as (which) grow (of themselves), which groweth of its own accord (itself).
see HEBREW caphach
H5599. caphiyach
I. [סָפִיחַ] noun [masculine] outpouring ?; — plural suffix הָאָרֶץ עֲפַר תִּשְׁטֹףסְֿפִיחֶיהָ Job 14:19 (si vera lectio) its outpourings sweep away the dust of the earth, so most, but dubious; Bu proposes *סְחִיפָה, compare סֹחֵף מָטָר Proverbs 28:3.
II. סָפִיחַ noun [masculine] growth from spilled kernels ((kernels) poured out, accidentally, in harvesting, according to most; BuhlLex 13 and others think of additional growth, √ I. ספח); — it is what springs up of itself in second year, and serves as food when no grain could be sown: absolute ׳ס 2 Kings 19:29 = Isaiah 37:30; construct קְצִירְךָ סְפִיחַ Leviticus 25:5; suffix אֶתסְֿפִיחֶיהַ תִּקְצְרוּ 25:11.