Other forms: fiercest, fiercer
Fierce means wild and ready to attack. A dog throwing itself at a fence with its teeth showing, a cat backed into a corner with its ears flat, the bird that dives at your head when you walk too close to the nest.
From animals the word moves to anything strong enough to hurt you: a fierce wind, fierce heat, a fierce argument that empties the room. Sport and business run on it — fierce competition, fierce rivals, a fierce contest for one job. It also fits feelings that burn rather than threaten: fierce loyalty, fierce pride, a fierce love for her children. The adverb is fiercely, and it does more work in writing than the adjective does: she defended him fiercely. One thing to keep straight — fierce is not brave. A fierce fighter frightens you; a brave one does not have to.
1adjectivefierceViolent and frightening, ready to attack.
“A fierce dog stood at the gate and would not let them past.”
2adjectiveintenseVery strong or intense.
“The two shops are in fierce competition for the same customers.”
3adjectivepassionateFelt very strongly; passionate.
“She has a fierce loyalty to the people who trained her.”
synonyms: passionate, ardent
Fierce came through Old French fers, which meant wild and ferocious, from Latin ferus — wild, untamed, the word for an animal that had never been near a farm. Middle English took it as fers and kept the animal edge on it for centuries. The fierce competition in a modern job advert is that same beast, with the teeth filed down.
Latin
ferus — wild", "untamed
Old French
fers — wild", "ferocious
Middle English
fers
English, today
fierce
From Middle English fers, fiers, borrowed from Old French fers (“wild", "ferocious”), nominative of fer, from Latin ferus (“wild", "untamed”).
Etymology from Wiktionary, CC BY-SA