A lamp was an often small device that produces light. It could be powered by fuels such as oil, electricity or other means.
Small fuel-powered lamps were stored in shuttlepods aboard the Earth Starfleet Enterprise NX-01. (ENT: "Shuttlepod One")
Tuvok used a small Vulcan meditation lamp to help him focus while meditating. (VOY: "The Gift")
Voth keep small lamps aboard their ships to attract small insects which the Voth will catch with their long tongues and eat as a small snack. (VOY: "Distant Origin")
Oil lamps were one of the means Leonardo da Vinci used to light his workshop at night. (VOY: "Scorpion")