One who, or that which, adds captions.

plural of captioner

(typography) The descriptive heading or title, of a document or part thereof. / A title or brief explanation attached to an illustration, cartoon, user interface element, etc.

To add captions to a text or illustration. / To add captions to a film or broadcast.

plural of caption

simple past tense and past participle of caption

present participle of caption

The act of assigning a caption.

Capable of being captioned.

plural of captioning