Leak

A leak occurs when something escapes from a structure designed to contain it.

Air leak[]

A faked plasma leak. (ENT: "Stratagem")
Enterprise NX-01 had a plasma leak caused by the unidentified aliens in 2151. (ENT: "Silent Enemy")
In 2368, a plasma leak aboard the USS Enterprise-D caused a warp core breach after a collision with the USS Bozeman. (TNG: "Cause And Effect")
A Skrreean starship suffered a plasma leak in its engine core in 2370. (DS9: "Sanctuary")
Deep Space 9's Lower Pylon One suffered a leak in 2370. (DS9: "Blood Oath")
A leak in a plasma injector caused a runabout to cross over into the mirror universe. (DS9: "Crossover")
In 2372, an attempt at creating an artificial wormhole caused significant damage to the USS Defiant, including a plasma leak in the engine room. DS9: "Rejoined")
The IKS Rotarran suffered a plasma leak on deck five in 2374, after the primary plasma injector was damaged in a Jem'Hadar attack. (DS9: "Sons and Daughters")
In 2376, Harry Kim was fixing a plasma leak on deck five when he began having a panic attack. (VOY: "Memorial")

In 2153, a coolant leak was part of a simulated shuttle flight. (ENT: "Stratagem")
Shuttlepod 2 leaked plasma coolant when its thrusters were damaged after it grazed a rock face. (ENT: "Strange New World")
In 2266, the toxic fumes from a coolant leak in the phaser system killed USS Enterprise crewman Robert Tomlinson during an engagement with a Romulan Bird-of-Prey. (TOS: "Balance of Terror")
A coolant leak was caused by collision with a quantum filament. (TNG: "Disaster")
A coolant leak occurred during an alternate timeline battle with Klingons. (TNG: "Yesterday's Enterprise")
In 2371, a coolant leak caused by battle damage led to the warp core breach that destroyed the USS Enterprise-D for the final time. (Star Trek Generations)

In 2366, radiation that had leaked from Doctor Nel Apgar's station in orbit of Tanuga IV threatened the USS Enterprise-D's antimatter pod. If the radiation had surged in or near them, it would have destroyed the ship. (TNG: "A Matter of Perspective")
In 2367, the USS Enterprise-D discovered a small Talarian observation craft adrift in Sector 21947. The craft had developed a serious radiation leak in its propulsion system. (TNG: "Suddenly Human")
In 2367, a massive radiation leak from a waste barge threatened to exterminate all life on Gamelan V. (TNG: "Final Mission")
In 2368, when the starboard power coupling overloaded on the USS Sutherland, there was a radiation leak on decks 10 through 12. (TNG: "Redemption II")
In 2370, a high-energy radiation leak was ignited by phaser fire, destroying a Skrreean ship. (DS9: "Sanctuary")
A radiation leak from a loose plasma coil on an Bajoran transport prevented the beam-off of an injured Vedek Bareil Antos. (DS9: "Life Support")
An antimatter radiation leak from Earth probe Friendship 1 caused radiation sickness to occur on a planet in the Delta Quadrant. (VOY: "Friendship One")
Malon waste export vessels could jettison their Theta storage tanks if a radiation leak occurred. (VOY: "Juggernaut")

A small gas leak. (ENT: "Doctor's Orders")
(ENT: "The Breach")
A beverage leak when drinking out of a trick glass. (TAS: "The Practical Joker")
A chlorinide leak. (TNG: "Ethics")
A beer leak occurred when the glass holding it was contaminated with invidium. (TNG: "Hollow Pursuits")
A thorium leak. (DS9: "Crossover")
Tamal became concerned about a neutrino leak in the port nacelle when Thomas Riker and the Maquis stole the USS Defiant. (DS9: "Defiant")
(VOY: "Learning Curve")
A fuel converter leaking veridium isotopes could cause a warp core breach. (VOY: "Drive")
In 21st century Earth slang, to "take a leak" means to urinate. (DS9: "Past Tense, Part I"; Star Trek: First Contact)