|buttocks||the two rounded parts we sit on, at the back of our body below the waist|
|button||a round fastening on clothes; any small knob|
|buttonhole||a narrow hole for a button to fit|
|buy||to give money in exchange for something|
|buzz||the humming sound a bee makes|
Defining relative clause
When a clause defines the noun it qualifies it is known as a defining relative clause.