legitimate

adjective

1 they have been given permission to run gambling halls, the only legitimate gambling in the area:

legal, lawful, licit, legalized, authorized, permitted, permissible, allowable, allowed, admissible, recognized, sanctioned, approved, licensed, statutory, constitutional, within the law, going by the rules, above board, valid, honest, upright;

informal legit, by the book.

▷antonyms illegal, illegitimate.

2 the legitimate heir:

rightful, lawful, genuine, authentic, real, true, proper, correct, authorized, sanctioned, warranted, acknowledged, recognized, approved, just;

informal legit, kosher;

British, informal pukka.

▷antonyms false, fraudulent.

3 these are legitimate grounds for unease:

valid, sound, admissible, acceptable, well founded, justifiable, reasonable, sensible, tenable, defensible, supportable, just, warrantable, fair, bona fide, proper, genuine, plausible, credible, believable, reliable, understandable, logical, rational.

▷antonyms invalid, unjustifiable.