Antonyms of adj treasonable

1 sense of treasonable

Sense 1
faithless, traitorous, unfaithful, treasonable, treasonous -- (having the character of, or characteristic of, a traitor; "the faithless Benedict Arnold"; "a lying traitorous insurrectionist")

INDIRECT (VIA disloyal) -> loyal -- (steadfast in allegiance or duty; "loyal subjects"; "loyal friends stood by him")

Similarity of adj treasonable

1 sense of treasonable

Sense 1
faithless, traitorous, unfaithful, treasonable, treasonous -- (having the character of, or characteristic of, a traitor; "the faithless Benedict Arnold"; "a lying traitorous insurrectionist")
       => disloyal (vs. loyal) -- (deserting your allegiance or duty to leader or cause or principle; "disloyal aides revealed his indiscretions to the papers")