Definition of propin:
(v) :
To pledge; to offer as a toast in the manner of drinking, that is, by drinking first and passing the cup.
(v) :
(by extension) To give in token of friendship.
(n) :
A gift or gratuity.
(v) :
To give, or deliver; to subject.
(n) :
A pledge.
(n) :
Alternative form of propyne. [(organic chemistry) the alkyne HC≡C-CH₃]