The Austronesian Comparative Dictionary

*leŋkuŋ concave, curved inward

PMP leŋkuŋ concave, curved inward

WMP
Tagalog ma-lukóŋ concave; hollow and curved; bowl-shaped, cup-shaped
lukuŋ-án to make something concave
lukóŋ concavity (of plates, basins, etc.)
Cebuano lúkuŋ make a coil, form a circle from something stiff
Malay ləŋkuŋ curved; curved; hollow
Rejang lekuŋ to bend; bent, as a tree that has not grown straight
Balinese lekuŋ concave
leŋkuŋ be bowed, bent, spherical; a bow, bend, semicircle
Sasak ləŋkuŋ bent, curved

POC loguŋ to bend

OC
Nggela loŋgu to bend, fold double, as bamboo tongs
loku to reef a sail; to make a coil of a fishing line
Sa'a loʔu to bend, to double back (as a pocketknife)
Arosi roku to fold up