Animals refers to in scientific usage, a multicellular organism that is usually mobile, whose cells are not encased in a rigid cell wall (distinguishing it from plants and fungi) and which derives energy solely from the consumption of other organisms (distinguishing it from plants). It commonly describes in non-scientific usage, any member of the kingdom Animalia other than a human, in non-scientific usage, any land-living vertebrate (i.e. not fishes, insects, etc.), and a person who behaves wildly; a bestial, brutal, brutish, cruel, or inhuman person, which gives the term a broader and more practical sense than a single short definition would suggest. Depending on context, it can also point to a person of a particular type and matter, thing, so the category can cover literal uses, related ideas, and more figurative extensions of the same core meaning. Taken together, these meanings present Animals as a flexible theme rather than a narrowly technical label, covering the central idea people usually mean when they use the word while still leaving room for closely related senses that appear in real language. Animals therefore works well as a quotation category because it can hold direct statements about the subject, figurative uses that borrow its meaning, and broader reflections that stay anchored to the same central idea.
