A suicide attack is an attack designed to inflict the maximum amount of damage and causalities in an action where the perpetrators expect to be killed in the process.
The Breen starship tactic, Skotha Reverse utilises suicide attacks by Breen attack fighters to slow down enemy vessels. (The Dominion War Sourcebook: The Fires of Armageddon)
During the Liberation of Benzar the Romulan vessel, Otoroth was destroyed in a suicide run at a Jem'Hadar battle cruiser. (The Dominion War Sourcebook: The Fires of Armageddon)
Vastly outnumbered by the Federation Alliance fleet during the First Battle of Chin'toka the five squadrons of Jem'Hadar attack ships resorted to ramming the Klingon warships that engaged them, destroying or crippling fifteen Klingon vessels. (DS9: "Tears of the Prophet")
The IKS Gor'Vas destroyed a Breen battleship in the Chin'toka system during the Battle of the Three Suns with a suicide run. (The Dominion War Sourcebook: The Fires of Armageddon)
A suicide attack by a Jem'Hadar battle cruiser stripped the atmosphere of Sentala III during the Dominion War. (The Dominion War Sourcebook: The Fires of Armageddon)
During the Battle of Sol the USS Adventure attempted to ram the Mer'jot Ducmre to prevent it from firing its main weapon, which would have destroyed Earth. (Star Trek: Adventure: "Once More Unto the Breach")