In general, a filler is something that is used to fill gaps. Specialized meanings of the word "filler" include:

• Filler (animal food), dietary fiber and other ingredients added to pet foods to provide bulk
• Filler (linguistics), a sound spoken to fill up gaps in utterances
• Filler (materials), particles added to a matrix material, usually to improve its properties
• Filler (packaging), a machine designed to fill packaging, usually occurs in food packaging
• Filler (surname)
• Filler metal, metal added in the making of a joint through welding, brazing, or soldering
• Grain filler, a product that is used to achieve a smooth-textured wood finish
• Seat filler, a person who fills an empty seat during an event
• Star filler, a plastic insert in computer cables which separates wires

The fillér was the name of various small change coins throughout Hungarian history. It was the subdivision of the Austro-Hungarian and the Hungarian korona, the pengo and the forint. The name derives from the German word Vierer that means 'number four' in English. Originally it was the name of the four-Kreuzer coin. Due to significant inflation that took place after the fall of Communism, fillér coins are no longer in circulation. The last fillér coin, worth 50 fillér (0.5 forint) was removed from circulation in 1999. However, it continues to be used in calculations, for example in the price of petrol (e.g. 310.9 HUF), or in the prices of telephone calls.