unbelievably

unbelievably — adverb

1. so extremely or in such a surprising way that it is hard to accept something as

1.adverbB2
Definition

so extremely or in such a surprising way that it is hard to accept something as true or real — used when something is much better, worse, faster, or more surprising than you would normally expect

Example

The weather in Taipei was unbelievably hot last summer.

degree modifier before adjective

Felix played the piano unbelievably well at the school concert.

degree modifier before adverb

Common collocations
  • unbelievably hot
  • unbelievably good
  • unbelievably bad
  • unbelievably fast
  • unbelievably slow
  • unbelievably beautiful
  • unbelievably important
  • unbelievably well
  • unbelievably + comparative adjective
Synonyms
  • incredibly

    the most common near-synonym; interchangeable in most degree contexts

  • astonishingly

    more formal and slightly stronger, often used with surprising achievements or statistics

  • remarkably

    more positive tone; suggests admiration rather than shock

  • extremely

    more neutral and factual, without the 'hard to believe' nuance; simply marks a high degree

Antonyms
  • predictably

    the opposite — something happens as expected, not surprisingly

Grammar Patterns

unbelievably + adjective

unbelievably + adverb

Unbelievably, + clause

verb + unbelievably

Usage Note

When used as a sentence adverb (e.g., 'Unbelievably, she won the race'), the clause that follows must express something genuinely surprising — not an everyday event.

Common Mistakes

I unbelievably finished my dinner.
Unbelievably, I finished my dinner in ten minutes.
When used as a sentence adverb, position the word at the start of the clause to make the surprising meaning clear.
The film was unbelievably.
The film was unbelievably boring.
As a degree modifier, 'unbelievably' must be followed by an adjective or another adverb; it does not work as a standalone complement after 'be'.

Word family

Synonym discussion

Sense: adverb/1

Unbelievably, incredibly, and astonishingly all express that something goes beyond normal expectation, but they differ in tone. 'Incredibly' is the most neutral and widely used — it fits both formal and casual contexts ('The view was incredibly beautiful'). 'Astonishingly' carries stronger emphasis and is more common in formal or written English, often paired with statistics or achievements ('Astonishingly, 90% of the patients recovered'). 'Remarkably' leans positive and suggests admiration rather than shock ('Her English improved remarkably in one year'). 'Extremely' is more neutral and factual, without the 'hard to believe' nuance — it simply marks a high degree ('extremely hot'). Use 'unbelievably' when you want to emphasize that something is so extreme it challenges belief, and 'extremely' when you just want to say 'very' without the surprise element.

incredibly ↗astonishinglyremarkably ↗extremely ↗

Common collocations

Adverbs

Phrases

  • so ... (that) ...
  • such ... (that) ...

Etymology

Old EnglishMiddle EnglishEnglish

Formed from the prefix 'un-' (meaning 'not'), added to 'believable' (able to be believed), which itself comes from the verb 'believe' (from Old English 'belēfan', meaning to have faith or trust) plus the suffix '-able'. The adverb ending '-ly' was then added. The word entered English in the mid-1500s and was originally used mostly for things that were literally too strange to be believed.