Letdown vs. Let Down
“Letdown” is a closed noun meaning a disappointment. “Let down” is the two-word phrasal verb, including the common sense of disappointing someone by failing to do what was expected.
Use “letdown” for the noun meaning a disappointment. Use “let down” as the verb, as in “Don’t let the team down.”
Key details
Choose the right form
| Meaning / situation | Form / construction | Decision |
|---|---|---|
| noun meaning disappointment | letdown | Use one word. |
| verb phrase meaning disappoint/lower/release | let down | Use two words. |
Quick tests
Meaning / construction test
Is the expression naming a disappointment as a noun?
If yes: Use “letdown.”
If no: If it is functioning as a verb, use “let down.”
Examples
The cancellation was a major letdown.
The noun is one word.
Please do not let the team down.
The phrasal verb is two words.
They let down the rope slowly.
The literal phrasal verb is also two words.
Further guidance
Core difference
Use the documented noun or modifier form when naming a thing, result, person, or concept; use the spaced form when the words function as a verb.
Fast Test
If the expression can take ordinary verb tense or inflection in the sentence, the spaced verb form is usually the relevant choice.
Variant Boundary
Cambridge separates the closed noun “letdown” from the two-word phrasal verb “let down.”
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- LETDOWN — English meaning (opens in a new tab)Cambridge Dictionary · Closed noun “letdown” meaning a disappointment
- LET DOWN — English meaning (opens in a new tab)Cambridge Dictionary · Two-word phrasal verb “let down”, including disappoint and related senses