vastly

adverb

vast·​ly ˈvast-lē 

: to a very great or vast degree or extent : exceedingly

two people with vastly different tastes

a vastly more powerful bomb

But bluff and bravado … won against potential enemies who vastly outnumbered him.

—David Gilmour

It was the most eclectic—yet also vastly entertaining—evening of dance I have seen in a long time.

—Rita Felciano

Synonyms of vastly

• extremely
• incredibly
• very
• highly
• terribly
• too
• greatly
• severely
• badly
• so
• far
• damned
• wildly
• damn
• really
• desperately
• heavily
• much
• seriously
• intensely
• immensely

Examples of vastly in a Sentence

the team has vastly improved in the course of the season

vastly underestimated the cost of advertising the new product

Recent Examples on the Web

And so vastly different from each other. —Brent Lang, Variety, 7 Jan. 2026

And cool-girl of the moment, Dakota Johnson, said bye to plain white sneakers, instead replacing them with a vastly underrated style that’s going to blow up this year. —Eva Thomas, InStyle, 7 Jan. 2026

This is not recommended, as the dietary needs of cats and dogs versus birds are vastly different. —Madeline Buiano, Martha Stewart, 6 Jan. 2026

The Patriots are a vastly different team under Vrabel – the 14-3 record is obvious evidence of that – but Harbaugh wouldn’t get into specifics about what exactly has changed them into a legitimate Super Bowl contender. —Greg Dudek, Boston Herald, 6 Jan. 2026

Word History

First Known Use

1598, in the meaning defined above

Rhymes for vastly

• ghastly
• lastly
• steadfastly