Reliable; worthy of trust.
Consistent with reality.
Loyal; adhering firmly to person or cause.
Injective in specific contexts, e.g. of representations in representation or functors in category theory.
Engaging in sexual relations only with one's spouse or long-term sexual partner.
Having faith.
Someone or something that is faithful or reliable.
The practicing members of a religion or followers of a cause.
Sly, dishonest, corrupt, cheating.
Done by moving the hand (and arm) from below.
Insincere; sarcastic.
An underhanded compliment is actually criticism.
Secret; surreptitious.
His underhanded trick backfired and he was disqualified.
Understaffed.
Devious people, collectively.
In an underhanded manner.