Synonyms of the word

authentic

• adj. Of the same origin as claimed; genuine.
• adj. Conforming to reality and therefore worthy of trust, reliance, or belief.
• adj. (music, of a Gregorian mode) Having the final as the lowest note of the mode.
• adj. (obsolete) authoritative.

echt

• adj. proper, real, genuine, true to type.

genuine

• adj. Belonging to, or proceeding from the original stock; native; hence, not counterfeit, spurious, false,…

reliable

• adj. Suitable or fit to be relied on; worthy of dependence or reliance; trustworthy.
• adj. (signal processing, of a communication protocol) Such that either a sent packet will reach its destination,…
• n. Something or someone reliable or dependable.

trustworthy

• adj. Deserving of trust, reliable.

trusty

• adj. Reliable or trustworthy.
• n. A trusted person, especially a prisoner who has been granted special privileges.

unquestionable

• adj. undeniable, obvious.

veritable

• adj. True, real.