Synonyms of the word

well-founded

• adj. based on reasoning, evidence and good judgement.
• adj. properly substantiated.
• adj. (mathematics) Of a binary relation: such that every non-empty subset of the relation's domain has a minimal…

reasonable

• adj. Having the faculty of reason; imbued with reason; rational.
• adj. Just; fair; agreeable to reason.
• adj. Not excessive or immoderate; within due limits; proper.
• adj. Not expensive; fairly priced.
• adj. Satisfactory.

sensible

• adj. (now dated or formal) Perceptible by the senses.
• adj. Easily perceived; appreciable.
• adj. (archaic) Able to feel or perceive.
• adj. (archaic) Liable to external impression; easily affected; sensitive.
• adj. Of or pertaining to the senses; sensory.
• adj. (archaic) Cognizant; having the perception of something; aware of something.
• adj. Acting with or showing good sense; able to make good judgements based on reason.
• adj. Characterized more by usefulness or practicality than by fashionableness, especially of clothing.
• n. (obsolete) Sensation; sensibility.
• n. (obsolete) That which impresses itself on the senses; anything perceptible.
• n. (obsolete) That which has sensibility; a sensitive being.

tenable

• adj. (of a theory, argument, etc.) capable of being maintained or justified; well-founded.
• adj. (of a defensive structure) capable of being defended against assault or attack; defensible.