insanity

Etymology

A three-part word (root 'sane', prefix 'in-' meaning 'not', suffix '-ity', meaning 'the state of'). Derived from Latin precursory equivalents. Two possible candidates for construction order: * insane + -ity: insānus (“unhealthy; insane”) + -itās *: Latin insānus (“unsound in mind; mad, insane”), from in- + sanus (“sound, sane”). Modern forms of roots: in- + sane * in- + sanity: in- (“lacking; without”) + sanitās (“health; sanity”) *: Latin sanitās (“sound in mind; sane”), from sānus + -itās. Modern forms of roots: sane + -ity

noun

1. The state of being insane; madness.
   The defendant pleaded insanity in the hope of getting a reduced sentence.