1. [for the ends of a flame] to reach out as the flame burns. The flames of the campfire flicked out and threatened the cold fingers that were too close. The flames flicked out from the burning house and set a nearby tree on fire.
2. [for the tongue of a reptile] to come out suddenly. The snake's tongue flicked out regularly. The lizard's tongue flicked out, grabbed the insect and ate it.
flick something out
[for a reptile] to push out its tongue quickly. The lizard flicked its tongue out repeatedly. The lizard kept flicking out its tongue at regular intervals.