Synonyms of the word 
OPENMOUTHED → GOGGLE-EYED - POPEYED - SURPRISED
openmouthed
- adj. Alternative form of open-mouthed.
goggle-eyed
- adj. Having prominent eyes; with eyes widely opened.
popeyed
- adj. having bulging eyes.
- adj. (by extension) astonished.
surprised
- adj. Caused to feel surprise, amazement or wonder, or showing an emotion due to an unexpected event.
- v. simple past tense and past participle of surprise.
If you are interested in words, visit the following sites :
- wiktionary.org/openmouthed For complete definition of a word
- 1word.ws/openmouthed to play with words, suffixs, prefixs, etc.