Honorarium
Honorarium , noun
[Latin honorarium (sc. donum), from honorarius. See Honorary, a.]
1.
A fee offered to professional men for their services; as, an honorarium of one thousand dollars. — S. Longfellow
2.
(Law) An honorary payment, usually in recognition of services for which it is not usual or not lawful to assign a fixed business price. — Heumann
Also: Honorary