Final answer:
The word 'foot' in the provided sentence refers to the anatomical part of the body used for standing and walking, and not to the unit of length measurement.
Step-by-step explanation:
The word foot in the sentence 'My right foot is bigger than my left foot.' refers to the anatomical term for the lower extremity of the leg below the ankle, on which a person stands and walks. It is not to be confused with the unit of measurement, which is also called a foot (plural: feet), where one foot equals 12 inches and is often abbreviated as 'ft'. The anatomical term 'foot' represents a specific part of the body, whereas when discussing measurements, such as the height of a door or the length of a car, the term refers to the unit of length in the customary system of measurement.