Treacherous.
Intending to entrap; alluring but harmful.
Hansel and Gretel were lured by the witch’s insidious gingerbread house.
Producing harm in a stealthy, often gradual, manner.
The battle was lost due to the actions of insidious defectors.
Extremely reckless.
Likely to commit, or to attempt to commit, suicide.
Highly likely to certain to result in the deaths of the participants; dangerous or reckless to such a degree as to be tantamount to suicide for those taking part.
Pertaining to suicide.
Someone suicidal; someone likely to kill themselves.