1. White-tailed Deer: This is the most likely meaning. "White hart" is an archaic or poetic name for a stag (male deer). In this context, "white hart deer" would simply be a white-tailed deer, particularly a male one.
2. Albino Deer: Some deer are born with albinism, a genetic condition that prevents them from producing melanin. This results in a white coat, pink eyes, and pale skin. A white hart deer could also be referring to an albino deer.
3. Leucistic Deer: Leucism is a condition similar to albinism, but it only partially reduces melanin production. This can result in a deer with a white or partially white coat but with normal eyes and skin pigmentation.
4. Symbolic Meaning: The "White Hart" is a symbol in English heraldry and folklore, often associated with King Richard II. It could be used metaphorically to refer to a noble or courageous individual.
To understand the meaning in a specific context, it's important to consider the source of the information.
If you provide more context, such as the source material where you encountered the term, I can provide a more definitive answer.