In his book "The Mother Tongue," Bill Bryson explores the concept of polysemy, which refers to words that have multiple meanings. This phenomenon is quite prevalent in the English language, as many words can convey different ideas depending on context. Understanding polysemy is essential for grasping the richness and complexity of language.

For instance, the word "sound" serves as an example of polysemy, as it can refer to auditory perception, a body of water, or even a general impression of something. Such variability in meaning illustrates how language evolves and how context shapes our understanding of words.