The phrase "to write a definition" means to explain or describe the meaning of a specific word or concept in words, usually in a clear and concise manner. Full definition
But don't stop there: Go over each of the terms, write them on the board and have students write the definition of each word - without the use of a dictionary. (thoughtco.com)
It is very convenient to place an order online instead of writing definition essays or research papers on your own. (grand-essays.com)
They may use a dictionary to look up any unfamiliar words, but they then must write a definition in their own words. (tes.com)