LSDvsluxWhat's the difference?

Which to use

“LSD” and “lux” are a confusable French pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#26,788
“LSD” frequency rank
#18,246
“lux” frequency rank
45034
confusion score

Side-by-Side Comparison

Feature LSD lux
Definition Composé organique de la famille des ergolines, le diéthylamide de l’acide lysergique, dérivé de l’acide lysergique présent dans l’ergot de seigle, connu comme un hallucinogène très puissant actif à de très faibles doses. Unité de mesure d’éclairement lumineux du Système international, définie comme lumen par mètre carré, dont le symbole est lx.

Where the eye mixes LSD and lux

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

3 ch
LSD
3 ch
lux

Visual trap between LSD and lux

A purely visual mix-up. LSD (\ɛl.ɛs.de\) and lux (\lyks\) are said differently, so reading them aloud is the quickest way to catch the wrong one. On the page they stay close: they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 45034, derived from the frequency rank of both members and their visual similarity.

LSD is recorded at frequency rank #26,788, classified as anoun, pronounced \ɛl.ɛs.de\. lux is at rank #18,246, tagged as anoun, pronounced \lyks\.

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 45034, this pair ranks #205,904 of 440,172 scored French confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of LSD vs lux

Shared letters: l. Private to "LSD": ds. Private to "lux": ux.

"LSD" · 3 letters · shape CCC  ·  "lux" · 3 letters · shape CVC

Frequently Asked Questions

Is swapping "LSD" for "lux" ever safe?
No. They are said differently (\ɛl.ɛs.de\ versus \lyks\) and carry different meanings; reading the sentence aloud is usually enough to catch the wrong one.
Which is more common, "LSD" or "lux"?
"lux" is the more common of the two: it sits at frequency rank #18,246 in our French list, against #26,788 for "LSD". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

After this comparison

Eye-level mix-up between "LSD" and "lux" is sorted above. Next: full entries or other pairs that share a letter shape.

  • Full dictionary entry for "LSD" with definition, IPA, and generated misspellings. Word entry
  • Full dictionary entry for "lux" - compare definitions side by side with the headword page. Word entry
  • This pair ranks #205,904 of 440,172 scored French confusable pairs in this corpus vintage. Corpus statistics
  • "LSD" and "lux" also get mixed up with nearby pairs, the highest-scored neighbour is "lep vs LSD". Nearby pair

Confusion rank #205,904 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