From arah; a nude place, i.e. (literally) the pudenda, or (figuratively) a vacant space -- nakedness, proportion.
see HEBREW arah
H4626. maar
[מַעֲרֶה], מַ֫עַר noun [masculine] bare, naked place (hence Μαραθών, Marathon, according to LewyFremdw. 144); —
1 bare place, or space: construct מִמַּעֲרִהגָּֿ֑בַע Judges 20:33 bare (open) space of Geba' (si vera 1.; but see II. מַעֲרָב); כְּמַעַראִֿישׁ 1 Kings 7:36 according to the clear space on each (plate, see לוּחַ).
2 suffix מַעְרֵח Nahum 3:5 figurative of Nineveh (pudenda exposed in shameful punishment; compare עֶרְוָה).