means A small handheld device that produces a flame on demand, typically to light cigarettes, candles, or stoves.

from From "light" plus the agent suffix "-er" — literally a "thing that lights." The verb "light" goes back to Old English "lihtan," meaning to kindle or set ablaze, itself rooted in the same ancient source as "light" the noun. Curiously, the flame-making sense of "lighter" arrived relatively late, only after portable ignition gadgets became practical in the 19th and 20th centuries — before that, a "lighter" was just as likely to mean a flat barge used to unload ships (a wholly separate word, from a different sense of "light" meaning to lift or lighten a load).