mu vs mum, What's the Difference?

Which to use

“mu” is an unknown and “mum” is a noun - they look or sound alike but fill different roles in a sentence.

#18,336
“mu” frequency rank: #11,295
“mum” frequency rank: 29631
confusion score

Side-by-Side Comparison

Feature	mu	mum
Definition	Genitiv Singular des Personalpronomens mina	Ester aus Fettsäuren und langkettigen Alkoholen; Wachs

Letter map: mu vs mum

Shared letters muted; letters that set mu and mum apart highlighted. Shared run: 2.

2 ch

3 ch

mum

Role in the sentence - mu and mum

Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: mu is anunknown and mumanoun. On the page they differ by 1 extra letter(s) - “mu” sits inside “mum”. Our composite confusion score for this pair is 29631, derived from the frequency rank of both members and their visual similarity.

mu is recorded at frequency rank #18,336, classified as anunknown, pronounced […]. mum is at rank #11,295, tagged as anoun, pronounced [mum].

Glosses for this pair are partially populated in our dataset, but the full side-by-side definitions above should still guide you to the right choice.

With a confusion score of 29631, this pair ranks #1,763,266 of 2,006,359 scored German confusable pairs - a relatively easy-to-tell-apart pair.

Orthographic DNA of mu vs mum

Shared letters: mu. Private to "mu": -. Private to "mum": -.

"mu" · 2 letters · shape CV · "mum" · 3 letters · shape CVC

Frequently Asked Questions

Can "mu" and "mum" be used interchangeably?

No - they are not even the same part of speech. "mu" is an unknown and "mum" a noun, so a sentence built for one is usually ungrammatical with the other.

Frequency check: "mu" vs "mum" - which ranks higher?

"mum" is the more common of the two: it sits at frequency rank #11,295 in our German list, against #18,336 for "mu". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

Useful next steps

You've compared "mu" and "mum". Here's where to go from here.

Full dictionary entry for "mu" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "mum" - compare definitions side by side with the headword page. Word entry
This pair ranks #1,763,266 of 2,006,359 scored German confusable pairs in this corpus vintage. Corpus statistics
"mu" and "mum" also get mixed up with nearby pairs, the highest-scored neighbour is "mu vs puzzles". Nearby pair

Confusion rank #1,763,266 of 2,006,359 scored German pairs, corpus vintage 2026-09-03, not spelling advice.