Uruk literally meant "Orc", (derived from ancient Elvish Urku or Uruku, "Monster, Demon") but was used exclusively or at last mostly to describe the greater Soldier-Orcs.The Term was often used as abbreviated version or westronisation of Uruk-Hai but was sometimes also used to describe greater Orcs or Hobgoblins in general.
In Adûnaic Uruk was the general term for any sort of Orc-creature or Goblin, the word Urûk in Ansith derived from the númenórean term.Other derivations of the Name were Orog (Deep-Orcs), Orsimer (Avarin), Eüröz or Ugra (Plainstongue), Arakî (Old Wômarin), Rakhās (Khuzdul), Ruk, Tanarukk etc..