Polysemy

Polysemy refers to the concept of words with multiple meanings, such as "The child started to walk" and "My mother used to dance the Lambeth Walk".

Although closely related in meaning to homonym, lexicographers distinguish between polysemes, different uses of the same word, as walk the dog, take a walk, Lambeth Walk, going walking, which they define in a single dictionary entry, and homonyms like fluke, which have multiple meanings and different etymologies, and are therefore separate definitions.

There is clearly a gray area between the two ideas, but homonyms are much better known to average speakers, while polysemes are a matter for specialists.