pac-, peac-, peas-

(Latin: peace, peaceful, calm, quiet; eased anger or agitation)

unpaid (adjective)
1. Without payment.
2. Awaiting payment or settlement; such as, unpaid bills.
3. Not yet in receipt of payment for work done.
4. Working without wages or a salary.
5. Serving without pay; unsalaried: "We worked as unpaid research assistants."
unpayable (adjective)
1. Services without payment: "They served in an unpayable volunteer fire department."
3. Engaged in as a pastime and so not payable; such as, an amateur painter which was unpayable.
3. Incapable of getting payment: "The bill was unpayable because we couldn't find the person who bought the dress."
Vade in pace.
Go in peace.

Another Roman way of saying, "goodbye".

Cross references directly, or indirectly, involving "calm, calmness, peace, quiet": plac-; quies-, quiet-; seren-.