Final answer:
A full, complex, multi-dimensional character is known as a round character, who has depth and undergoes development, unlike a flat character who remains one-dimensional.
Step-by-step explanation:
A full, complex, multi-dimensional character in literature is commonly known as a round character. This term was coined by E.M. Forster in 'Aspects of the Novel'. Round characters are contrasted with flat characters, who are simple and one-dimensional. Flat characters do not undergo significant change throughout the story, whereas round characters experience development and complexity, often undergoing personal growth or change. This distinction is key in understanding character dynamics in literary analysis. The correct answer to the question asked by the student is: A round character.