filler1

noun

• 1 [usually in combination] a thing put in a space or container to fill it:these plants are attractive gap-fillers or ground cover
• a substance used for filling cracks or holes in a surface, especially before painting it:quick-hardening wood filler
• material used to fill a cavity or increase bulk:foam filler good quality paints should contain little or no filler
• an item serving only to fill space or time, especially in a newspaper, broadcast, or recording.
• a word or sound filling a pause in an utterance or conversation (e.g., er, well, you know).
• a linguistic unit that fills a particular slot in syntactic structure.
• US the tobacco blend used in a cigar.

• 2 [in combination] a person or thing that fills a space or container:supermarket shelf-fillers