Word: Flabbergasted (adjective)
Definition: affected with sudden and great wonder or surprise
Source: https://www.merriam-webster.com/thesaurus/flabbergasted
Encounter: I encountered this word on a music video I happened to have watched over the weekend.
Comprehension: I comprehend that this word means being surprised in various ways. for example coming home to a surprise birthday party would make someone flabbergasted.