ὠφελητέον

α, ον
A. proper to be served, ὠφελγτέα σοι ἡ πόλις X. Mem. 3.6.3.
II. ὠφελητέον, one must serve, τὴν πόλιν ib.2.1.28.
Liddell, Scott & Jones
A Greek-English Lexicon, 1940
An open-access project