Good points! Almost no one replied to the actual question I started with so thanks!!
How bout these:
Kamikaze is a strategic sacrifice of troops without destroying your game entirely.
Suiciding is the strategically dubious play of destroying one’s position in an unretrievable way by smashing into an opponent or opponents troops for no discernible in game advantage.*
Cashing out: Is doing the same in a controlled way perhaps taking two or three kills on the way out. (I sometimes cash out for second place when I only see a winning line two hours in the future and very low probability). I guess that’s still a sort of suicide but it is strategic.
Punishment or Loser Choosing would be the delayed suicide when a player destroys your game and you wait for an opportune moment much later when your game is now completely lost but you can still damage their game in a meaningful way and assure that they go into the endgame with a much lower win probability.
King making / winner choosing would be when you cash out to assist an ally to the win after a long and enjoyable game but when your position is no longer tenable or you are out of time to play.
of course there are: Failed kills that lead to quick death, also a sort of suicide.
*I would place the caveat that while there is no in game route to the win reason for suiciding or loser choosing there is a tit for tat strategy that would warrant their occasional use not for in game advantage but for multi game advantage. If mutually assured destruction is never carried out then it has no meaning and players can always bully any player to death. If occasionally that type of play results in the sudden destruction of 80% of their troops they might think twice. This is the only real way that guarding with a threat stack works effectively. I hate Australia so much that when given it first turn I’ve sometimes experimented with trying to lose it / guarding it open with a threat stack in Asia and it is surprisingly effective.