filler

The word "filler" has several related meanings, and they all connect to the idea of taking up space or covering a gap. In the most literal sense, it means a material used to fill holes, cracks, or empty areas. You might use wall filler on drywall, wood filler on furniture, or another substance that smooths a surface before painting or repair.

The word is also used for anything added mainly to increase amount rather than quality. In food or manufactured goods, filler can mean cheap extra material used to bulk out the product. This use often sounds negative, because it suggests the product has less real value than it should.

In speaking, filler often means small words or sounds such as "um," "uh," "like," or "you know." These speech fillers help people hold the floor while they think, even though they can become distracting when overused. In writing, television, and conversation, filler can also mean extra material that does not add much value, such as a scene, paragraph, or episode included mostly to make something longer.

Another common modern use is in beauty treatment: facial filler is a substance injected under the skin to add volume and soften lines. So depending on context, "filler" may be useful, harmless, or mildly critical, but the core idea stays the same: something is being added to occupy space, extend something, or make up for what is missing.