Wiktionary
n. (context military English) An armoured fighting vehicle equipped with an antitank gun or missile launcher.
WordNet
n. an armored vehicle equipped with an antitank gun and capable of high speeds
Wikipedia
A tank destroyer or tank hunter is a type of armoured fighting vehicle, armed with a direct-fire artillery gun or missile launcher, with limited operational capacities and designed specifically to engage enemy armoured vehicles.
Tanks are generally armoured fighting vehicles designed for front-line combat which combine operational mobility and tactical offensive and defensive capabilities and perform all primary tasks of the armoured troops on the battlefield; the tank destroyer on the other hand is specifically designed mainly for taking on enemy armour. Many have been based on a tracked tank chassis, while others are wheeled.
Since World War II, gun-armed tank destroyers have fallen out of favor as armies have favored multirole main battle tanks. However, lightly armored anti-tank guided missile (ATGM) carriers are commonly used for supplementary long-range anti-tank work. The resurgence of expeditionary warfare in the past twenty years has seen the emergence of gun-armed wheeled vehicles, sometimes called "protected gun systems", which may bear a superficial resemblance to tank destroyers, but are employed as direct fire support units typically providing support in low-intensity operations such as the wars in Iraq and Afghanistan.
Usage examples of "tank destroyer".
It became a pattern: make contact, the infantry drop off and move forward under covering tank or tank destroyer fire, smash the strong point, remount and move on.
He was being given a father-to-son or, perhaps more accurately, a Dutch uncle talk prior to the announcement-or even prior to his figuring it out that he was to have command of the 3087th Aviation Company (Tank Destroyer) (Provisional).