The word fierce has several meanings, but generally it refers to something or someone that is intense, strong and aggressive. It can be used to describe a person with a very determined or forceful character, who shows great energy in pursuing their goals. Fierce can also refer to an animal that is wild and dangerous, such as a fierce lion or tiger. In some cases, it may imply anger or hostility, for example "a fierce argument" or "fierce opposition". The word comes from the Old French word "fer", meaning iron, which suggests strength and determination.