fearsome

adjective

fear·​some ˈfir-səm 

1

a

: causing fear

a fearsome monster

b

: intense, extreme

fearsome determination

2

: timid, timorous

fearsomely adverb

fearsomeness noun

Synonyms of fearsome

• formidable
• terrifying
• frightening
• scary
• horrible
• terrible
• intimidating

Examples of fearsome in a Sentence

at night the child would always imagine that there were fearsome monsters lurking under his bed

after working all afternoon in the hot sun, I had developed a fearsome thirst

Recent Examples on the Web

There’s also plenty of Duncan Idaho, the fearsome warrior who died defending Paul and his mother (Rebecca Ferguson), and who has been resurrected as a ghola. — Angelique Jackson, Variety, 8 July 2026

Not every invasive species is as dramatic or fearsome as a Burmese python or a feral hog—but that doesn’t lessen their impact on native ecosystems. — Andrew Paul, Popular Science, 8 July 2026

Now that these lovable chaos agents are joined by all manner of fearsome, gelatinous people-eaters, parents might be wondering whether to have their youngest tykes sit this installment out. — Patrick Ryan, USA Today, 1 July 2026

The 19-year-old Russian is the favorite given her form, but Krejčíková, 30, is a fearsome opponent on grass and will enter the match unburdened by pressure. — Ava Wallace, New York Times, 30 June 2026

Word History

Etymology

fear entry 1 + -some entry 1

First Known Use

1768, in the meaning defined at sense 1a

Kids Definition

fearsome

adjective

fear·​some ˈfi(ə)r-səm 

1

: causing fear

2

: timid

fearsomely adverb

fearsomeness noun