Word.ws English Dictionary

mulm

mulm noun: the sludge that collects at the bottom (or walls) of an aquarium, consisting of fish excrement, decaying plant matter, and other assorted detritus.

Noun

mulm (uncountable)

  1. The sludge that collects at the bottom (or walls) of an aquarium, consisting of fish excrement, decaying plant matter, and other assorted detritus
    • The point is that the filter not only removes mulm from the tank but also ensures that this matter is very efficiently bathed in a constant flow of water, which will dissolve out anything that can be dissolved.2013, C. W. Emmens, Keeping and Breeding Aquarium Fishes, page 115

Origin of mulm

Borrowed from German Mulm. Doublet of malm.

Questions about mulm

What does mulm mean?
Mulm means the sludge that collects at the bottom (or walls) of an aquarium, consisting of fish excrement, decaying plant matter, and other assorted detritus.
What part of speech is mulm?
Mulm is a noun.

Words near mulm in the dictionary

  1. Mullumbimby
  2. Mullumbimby Creek
  3. mullygrubber
  4. mullygrubbers
  5. mullygrubs
  6. mulm
  7. mulmul
  8. mulmull
  9. mulmulls
  10. mulmuls
  11. Mulmur

Source and license

Adapted from Wiktionary: mulm (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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Cite this entry: “mulm.” Word.ws, https://word.ws/mulm. Based on Wiktionary, CC BY-SA 4.0.