Definition of clip-on:
(v) :
To grip tightly.
(v) :
To fasten with a clip.
(v) :
(slang) To collect signatures, generally with the use of a clipboard.
(n) :
Something which clips or grasps; a device for attaching one object to another.
(n) :
An unspecified, but normally understood as rapid, speed or pace.
(n) :
(military) A frame containing a number of rounds of ammunition which is intended to be inserted into an internal magazine of a firearm to allow for rapid reloading.