vastly meaning and definitionDefinition and meaning of vastly at MeaningMonkey.org. vastly meaning and definition in the English Dictionary.
Definition of vastly (adverb)
- to an exceedingly great extent or degree
- "He had vastly overestimated his resources"; "was immensely more important to the project as a scientist than as an administrator"
- synonyms: immensely
Source: Princeton University Wordnet