rectitude

The word 'rectitude' entered English in the late Middle Ages via Old French from the Latin rectitudo, which itself was built from rectus (straight) and the noun-forming suffix -tudo. The Latin rectus originates from the past participle of the verb regere, meaning "to lead straight, to rule, to guide," which is traced back to the Proto-Indo-European root h₃reǵ- (to move in a straight line, to lead, to rule). The core semantic journey is from the physical concept of "straightness" to the metaphorical and moral sense of "rightness" or "correctness." Thus, rectitude literally means "the state or quality of being straight," which evolved to signify unwavering adherence to moral principles.

Structure: rect (straight) + itude (state or quality) - rect: From Latin rectus, meaning "straight, right, correct." It functions as the core root conveying the concept of correctness. - itude: From Latin -tudo, a suffix forming abstract nouns indicating a state, condition, or quality.