How to pronounce costume in American English
KAH·stoom
Start here
Americans pronounce costume as KAH-stoom (/ˈkɑstum/). Stress falls on the first syllable — keep everything else short and quick.
Now you try.
Record yourself saying "costume" and play it back. The mic stays on your device — nothing's uploaded.
In real conversation
Hear "costume" in the wild.
Click any sentence to see the full breakdown — every link, every reduction, every flap-T.
Watch out
Common pronunciation mistakes in American English.
The textbook way isn't wrong — it's just not how anyone actually says it.
01
Stressing the wrong syllable.
Stress falls on the first syllable, not the others. Stretch KAH — keep everything else short and quick.
kah·STOOM→KAH·stoom
Questions
Questions people ask about this.
How is "costume" stressed in American English?
Stress falls on the first syllable — say "KAH" with a longer, fuller vowel and keep every other syllable short and quick. The respell "KAH-stoom" marks the stressed syllable in capitals so the rhythm is easy to read at a glance.
Is the American pronunciation of "costume" different from British English?
American English uses different vowel shapes, a relaxed retroflex R, and connected-speech tricks like flap-T and glottal-stop T that British Received Pronunciation generally avoids. The respell "KAH-stoom" reflects the casual American form; British dictionaries typically print a citation form with crisper consonants and different vowel choices.
Stop reading about "costume". Start saying it.
SayWaader is the AI pronunciation coach for American English. Practice 5 minutes a day. Get a 5-axes accent assessment. Sound like you live here.