Mental Illness That's a Possible Defense Plea

This page is the CodyCross answer for the clue below from World of Sounds, Group 1360, Puzzle 1 (Ambulance Siren).

Question is: Mental Illness That's a Possible Defense Plea

and the answer is: INSANITY

Word Meaning:

INSANITY — The state of being insane; madness.

Definitions from Wiktionary.