The definition of insane is someone who acts or speaks strangely because their brain isn’t working correctly.(adjective)
An example of insane is a person who goes shopping without any pants on.
Insane is defined as very foolish or senseless behavior.(adjective)
An example of insane is a person who goes on an expensive vacation after just losing a job.
See insane in Webster's New World College Dictionary
Origin: L insanus
See insane in American Heritage Dictionary 4
Origin: Latin īnsānus
Origin: : in-, not; see in-1
Origin: + sānus, sane, healthy.
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