A contusion, or bruise, was a traumatic injury in which blood vessels beneath the skin broke. A bruised eye socket was referred to as a black eye.
In September 2152, when Enterprise NX-01 traversed a neutronic storm and the starship's crew consequently had to hide in the vessel's catwalk, a "few bumps and bruises" from the turbulence were the only injuries the crew suffered from during their transit into that part of the ship. (ENT: "The Catwalk")
In 2370, Quark was treated by Doctor Julian Bashir and Yeto for a potentially fatal contusion of his auricular lobe. (DS9: "Invasive Procedures")
The following year, when the crew of the USS Voyager met Kes for the first time on the surface of Ocampa, she had bruises around her left eye from having been tortured by the Kazon-Ogla. The Doctor later treated the bruises in Voyager's sickbay. (VOY: "Caretaker")
On a planet in the Delta Quadrant, Kathryn Janeway and several protesters received bruises when security officers hit them with their batons. (VOY: "Time and Again")
By running a bio analysis, Tom Paris managed to identify bruises on Kes' neck as the result of a Vulcan neck pinch. (VOY: "Cathexis")
In 2372, Miles O'Brien's trachea was bruised by the Jem'Hadar Temo'Zuma on Bopak III. (DS9: "Hippocratic Oath")
Tuvok had several bruises on his face after he was interrogated, later that year, by soldiers of the Mokra Order. (VOY: "Resistance")
In 2373, Quark suffered multiple contusions, among other injuries, after spending time with Grilka. (DS9: "Looking for par'Mach in All the Wrong Places")