λογικός

Etymology
From.

Adjective

 * 1) Belonging to speech: prose
 * 2) Belonging to reason: intellectual
 * 3) rational, logical, reasonable, thoughtful

Adjective

 * 1) logical, rational
 * 2) reasonable
 * 3) sensible (Acting with or showing good sense; able to make good judgements based on reason)

Noun

 * 1) a sane person