Also, the word could refer to the mammals of the Order Carnivora, many (but not all) of which fit the first definition. Bears are an example of members of Carnivora that are not true carnivores. Carnivores that eat primarily (or only) insects are called insectivores.
A true carnivore is an animal that subsists primarily on a diet consisting only of meat. They may consume other products presented to them, especially animal products like cheese and bone marrow, or sweet sugary substances like honey and syrup, but do not need to consume these on a regular basis. True carnivores lack the physiology required for the digestion of vegetable matter.
Domesticated carnivores are often recommended to have vegetable supplements (or such containing processed pet foods) as meats designed for human consumption may be lacking in vital nutrients.