having competence in a task, being effective at producing a desired outcome.
At least, that is what this means when modifying an animate noun. When modifying an inanimate noun, it means “functional, operational, in working order” and is derived from the root for ‘light’ with the suffix noting an artificial construct. One would think, therefore, that this word would mean something along the lines of “emitting artificial light”, and that is an obsolete meaning. Due to more complicated devices having a light to indicate that the device is operational, this word came to mean what it does now.