Bounden

p. p & a.	1.
	1.	Bound; fastened by bonds.
	2.	Under obligation; bound by some favor rendered; obliged; beholden. This holy word, that teacheth us truly our bounden duty toward our Lord God in every point. - Ridley.
	3.	Made obligatory; imposed as a duty; binding. I am much bounden to your majesty. - Shak.

Adj.

1.

bounden - morally obligatory; "my bounden duty"

obligatory