PS

*labb(-at)-, *lab(y)-ān- - (animal's) body from neck to rump (SED I No. 173)

Meaning somewhat diffuse (originally may denote trunk as a whole). Semantically and phonetically (­a­ vs. ­) rather to be separated from *libb-­ ‘heart’. 

Akkadian
labânu - tendon of the neck; neck (CAD l 12, AHw 524)

The underlying form is *laby-ān­ (with suffix ­-ān). 

Arabic
lubbat- - the upper chest that meets the collarbone (BK 2 955)

The suffix -ān­ in labān-. 

Arabic
labbat- - upper part of the chest, low neckline, throat (WKAS II 84)
Arabic
labān- - chest, especially the part between the teats, chest (of any hoofed animal); breast (BK 2 962, WKAS II 169)
Arabic
labab- - the top of the chest or chest from which descends a necklace or other neck adornment; chest strap (of horse etc.) (BK 2 955; WKAS II 83)
Tigre
läbbät - place of the fillet steak on the back of animals; midst, side (WTS 39 )
Wolane
labä - waist (EDG 373)
Zway
läbät - podex, anus, buttocks (EDG 374 )
Chaha
naba - waist (EDG 373 )
Ezha
naba - waist (EDG 373 )
Ennemor
naḇa - waist (EDG 373 )
Gyeto
naḇa - waist (EDG 373 )
Muher
laba - waist (EDG 373 )
Masqan
laba - waist (EDG 373 )
Gogot
laba - waist (EDG 373 )
Soddo
laba - waist (EDG 373 )
Mehri
məlább - side (ML 250 )
Jibbali
lɛb - side (in fixed expressions) (JL 159 )