#753 PTB *m/p/s-(l/d)ap ARM / HAND / WING

This well-established root is attested in the North Assam group and Himalayish. The basic allofam has a simple lateral initial, but several prefixes (p‑ and n‑) are also attested. The initial is realized as a dental stop after the nasal prefix (see n‑dap below). Possibly ultimately related is the root yaːp “wave, fan, paddle” [HPTB p.340]

There is a similar root #824 PTB *s‑lap LEAF / LEAFLIKE PART (STC #321), with perhaps the same origin, the connection being the perceived flatness of leaves and wings.