From an unused root probably meaning to polish; the (human) skin (as smooth) -- skin.
Englishman's Concordance
1) skin (human) Part of Speech: noun masculine A Related Word by BDB/Strong’s Number: from an unused root probably meaning to polish Same Word by TWOT Number: 349
Brown-Driver-Briggs
[גֶּ֫לֶד] noun masculineskin (Arabic , Aramaic גִּלְדָּא, ) of man Job 16:15שַׂק תָּפַרְתִּי עֲלֵי גִלְדִּ֑י.
Job 16:15 HEB:תָּ֭פַרְתִּי עֲלֵ֣י גִלְדִּ֑י וְעֹלַ֖לְתִּי בֶעָפָ֣ר NAS: over my skin And thrust KJV: sackcloth upon my skin, and defiled INT: have sewed over my skin and thrust the dust