jaw-dropping
adjective
jaw-drop·ping ˈjȯ-ˌdrä-piŋ 
: causing great surprise or astonishment
jaw-dropper
ˈjȯ-ˌdrä-pər
noun jaw-droppingly
ˈjȯ-ˌdrä-piŋ-lē
adverb 
Synonyms
- amazing
- astonishing
- astounding
- blindsiding
- dumbfounding
- dumfounding
- eye-opening
- flabbergasting
- jarring
- jolting
- shocking
- startling
- stunning
- stupefying
- surprising
See all Synonyms & Antonyms 
Word History
First Known Use
1980, in the meaning defined above
jaw-dropper
noun
as in surprise
something that makes a strong impression because it is so unexpected the underdog's victory was a jaw-dropper in boxing circles Synonyms & Similar Words
Relevance
- surprise
- shock
- stunner
- jolt
- revelation
- bombshell
- shocker
- surprize
- kicker
- bolt out of the blue
- bolt from the blue
- jar
- marvel
- thunderclap
- wonder
- eye-opener
- amazement
- twist
- fillip
- wrinkle
- kick