Fraught with terror; fearful, dreadful, terrible.

Causing fright, formidable.

Feared, dreaded.

Causing trouble or fear, dreadful. Obsolete.

Causing fear; inspiring terror, reverence, or awe; dreadful, terrible, awful.

Esp. of a person: revered, respected; noted, distinguished; (also) formidable, feared. Cf. redoubtable, adj.

To be dreaded or feared; awful, dread. Obsolete.

feared.

= redoubted, adj.

Esp. of a person: that is to be revered, commanding respect; formidable, esp. as an opponent; that is to be feared or dreaded.

To be dreaded; redoubtable, dread. Obsolete.

Fearful, frightful.

Feared, dreaded, redoubted. Obsolete.

That gives cause for fear or alarm; fit to inspire dread or apprehension. Now usually (with some obscuration of the etymological sense): Likely to…

In early use: †frightening, terrifying, alarming (obsolete). Later: shocking, horrifying.

In senses of fear, v. 5 7: Regarded with fear; anticipated or suspected with uneasiness; †apprehensively supposed to be such.

Causing fright; frightening, frightful. Also in weakened use as an intensifier.

Frightful.

That frightens.

Fear-inspiring; frightful, dreadful.

Frightful, dreadful.

Giving cause for fear; to be feared.

Belligerent or intimidating; ruthless; tough. Also as a general term of approval: formidable, superlative (cf. bad, adj. 13).

= badass, adj.

slang (originally in African-American usage). Of a person: very tough, formidable. Also as a general term of approbation: very good, extremely…