Which to use
“mad” is an adjective and “MD” is a noun - they look or sound alike but fill different roles in a sentence.
- #1,868
- “mad” frequency rank
- #5,143
- “MD” frequency rank
- 7011
- confusion score
Side-by-Side Comparison
| Feature | mad | MD |
|---|---|---|
| Definition | Insane; crazy, mentally deranged. | Symbol (usually a postnominal) indicating a medical degree; medical physician or medical doctor; doctor(ate) of medicine |
Letter map: mad vs MD
Shared letters muted; letters that set mad and MD apart highlighted. Shared run: 2.
Grammar separator: mad vs MD
Our dataset has no pronunciation recorded for both members, so the reliable separator here is grammatical: mad is anadjective and MDanoun. On the page they differ by 1 letter(s) in length. Our composite confusion score for this pair is 7011, derived from the frequency rank of both members and their visual similarity.
mad is recorded at frequency rank #1,868, classified as anadj, pronounced /ˈmæd/. MD is at rank #5,143, 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 7011, this pair ranks #508,972 of 530,003 scored English confusable pairs - a relatively easy-to-tell-apart pair.
Orthographic DNA of mad vs MD
Shared letters: dm. Private to "mad": a. Private to "MD": -.
"mad" · 3 letters · shape CVC · "MD" · 2 letters · shape CC
Frequently Asked Questions
Is swapping "mad" for "MD" ever safe?
Which is more common, "mad" or "MD"?
After this comparison
Done with this confusable. These links stay specific to "mad" and "MD".
- Full dictionary entry for "mad" with definition, IPA, and generated misspellings. Word entry
- Full dictionary entry for "MD" - compare definitions side by side with the headword page. Word entry
- This pair ranks #508,972 of 530,003 scored English confusable pairs in this corpus vintage. Corpus statistics
- "mad" and "MD" also get mixed up with nearby pairs, the highest-scored neighbour is "MD vs MMP". Nearby pair
Confusion rank #508,972 of 530,003 scored English pairs, corpus vintage 2026-09-03, not spelling advice.