noun, na-adjective, noun which may take the genitive case particle 'no'
straightforward honesty; single-minded honesty
Describes a person or attitude that is uncompromisingly honest, often to the point of being naive or inflexible. Can be used as a noun, na-adjective, or no-adjective.
彼は正直一途な性格で、嘘をつくことができない。
He has a straightforwardly honest personality and cannot tell a lie.
正直一途の生き方は時に損をすることもある。
A life of single-minded honesty can sometimes be disadvantageous.
Compound of 正直 (honesty) and 一途 (single-minded, earnest). The exact historical derivation is uncertain, but the combination straightforwardly conveys 'single-minded honesty'.