a. hợp lệ, hợp thức, đoan chính, phong nhã

socially or conventionally correct; refined or virtuous: respectable, nice
in the right manner: right, in good order, decently, properly, the right way
according with custom or propriety: comme il faut, becoming, seemly, comely, proper, decorous
decently clothed: modest
observing conventional sexual mores in speech or behavior or dress: modest
conforming to conventions of sexual behavior: proper, decorous, clean, unobjectionable
sufficient for the purpose: adequate, sufficient, enough