Fornander:

"PENA, v.  Marqu., to create, work, make, prepare. Sam., pena, to cut up, as a pig, to snare. Tah., pena, penapena, to bring up the rear of an army, to cover, protect the helpless.

Greek, πενομαι, to work, toil, prepare; πενεστης, a labourer, workman; πενης, id., a poor man; πονος, work, toil, drudgery; πονεω, work hard, to toil, suffer.

It may be for want of a better etymology that the Latin pæne, pene, near by, almost; penula, a cloak, covering, outer garment, refer themselves to this family of words, in some forgotten sense analogous to the Tahitian pena.

In the West Aryan branches, the derivative sense of 'pain, suffering, want', was developed from the primary idea of 'working, working hard', and found expression in words like - Greek, πενια, πεινα, ήπανια, &c; Lat., penuria, pæna, punio; Sax., pine; Slav., pina; but seems to have been unknown to the Polynesians."