spy vs STS, What's the Difference?

Which to use

“spy” and “STS” are a confusable English pair: similar on the page, but distinct in meaning, check the gloss before you choose.

#4,799
“spy” frequency rank: #20,790
“STS” frequency rank: 25589
confusion score

Side-by-Side Comparison

Feature	spy	STS
Definition	A person who secretly watches and examines the actions of other individuals or organizations and gathers information on them (usually to gain an advantage).	Initialism of science and technology studies.

Letter map: spy vs STS

Shared letters muted; letters that set spy and STS apart highlighted. Shared run: 1.

3 ch

spy

3 ch

STS

Corpus notes: spy and STS

spy and STS are indexed as a confusable English pair. We have no recorded pronunciation or part of speech for both members, so the spelling overlap is what we can show you: they share most of their letters but differ in 2 positions. Our composite confusion score for this pair is 25589, derived from the frequency rank of both members and their visual similarity.

spy is recorded at frequency rank #4,799, classified as anoun, pronounced /spaɪ/. STS is at rank #20,790, tagged as anoun.

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 25589, this pair ranks #393,123 of 530,003 scored English confusable pairs - roughly mid-pack for confusability.

Orthographic DNA of spy vs STS

Shared letters: s. Private to "spy": py. Private to "STS": t.

"spy" · 3 letters · shape CCV · "STS" · 3 letters · shape CCC

Frequently Asked Questions

Do "spy" and "STS" mean the same thing in a sentence?

No. They share most of their letters but differ in 2 positions, but the dictionary glosses above give them different meanings, so swapping one for the other changes what the sentence says.

Which is more common, "spy" or "STS"?

"spy" is the more common of the two: it sits at frequency rank #4,799 in our English list, against #20,790 for "STS". The two are close in frequency, so neither is a safe default; check the meaning rather than guessing.

What to do next

Pair "spy" vs "STS" is on the table, pick a follow-up below.

Full dictionary entry for "spy" with definition, IPA, and generated misspellings. Word entry
Full dictionary entry for "STS" - compare definitions side by side with the headword page. Word entry
This pair ranks #393,123 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
"spy" and "STS" also get mixed up with nearby pairs, the highest-scored neighbour is "STS vs suds". Nearby pair

Confusion rank #393,123 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.