DSTvsdumWhich spelling fits?

Quick tell: DST is a name, dum is a preposition, so they fill different roles in a sentence.

Which to use

“DST” is a name and “dum” is a preposition - they look or sound alike but fill different roles in a sentence.

#43,896
“DST” frequency rank
#37,286
“dum” frequency rank
81182
confusion score

Side-by-Side Comparison

Feature DST dum
Definition Service de renseignement, organisme d’État fusionné en 2008 avec la Direction centrale des Renseignements généraux (RG) pour donner naissance à la DCRI. Pendant, durant, pendant que, tandis que.

Where the eye mixes DST and dum

Muted = shared; highlighted = the visual trap. They share 1 letter in sequence.

3 ch
DST
3 ch
dum

Why the eye confuses DST with dum

These two trip readers on the page rather than in the ear: DST is \de.ɛs.te\ while dum is \dum\. Spoken aloud the problem disappears. In writing it persists, because they share most of their letters but differ in 2 positions, and the parts of speech differ too (name vs preposition), which is usually the fastest check. Our composite confusion score for this pair is 81182, derived from the frequency rank of both members and their visual similarity.

DST is recorded at frequency rank #43,896, classified as aname, pronounced \de.ɛs.te\. dum is at rank #37,286, tagged as aprep, pronounced \dum\.

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 81182, this pair ranks #19,313 of 440,172 scored French confusable pairs - among the most confusable pairs.

Orthographic DNA of DST vs dum

Shared letters: d. Private to "DST": st. Private to "dum": mu.

"DST" · 3 letters · shape CCC  ·  "dum" · 3 letters · shape CVC

Frequently Asked Questions

Can "DST" and "dum" be used interchangeably?
No - they are not even the same part of speech. "DST" is a name and "dum" a preposition, so a sentence built for one is usually ungrammatical with the other.
Which is more common, "DST" or "dum"?
"dum" is the more common of the two: it sits at frequency rank #37,286 in our French list, against #43,896 for "DST". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Pronunciation already separates them, if the page still looks alike, the dictionary links below settle it.

  • Full dictionary entry for "DST" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "dum" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #19,313 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "DST" and "dum" also get mixed up with nearby pairs, the highest-scored neighbour is "DCI vs DST". Nearby pair

Confusion rank #19,313 of 440,172 scored French pairs, corpus vintage 2026-09-03, not spelling advice.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list