bob
UK[bɒb]US[bɑːb]
v
to move up and down quickly and repeatedly, especially on water
n
a short, simple hairstyle for women and children in which the hair is cut to the same length all around the head just below the ears
n
a quick, short movement up and down
Etymology
the word 'bob' is a classic example of a native english word of imitative origin, first appearing in middle english. its core sense is thought to mimic the sound and motion of a light, repetitive bump or bounce, such as a cork floating on water. from this fundamental idea of short, jerky movement, the word semantically expanded to describe a variety of quick actions, including the curtsey-like 'bob' of respect and the quick cut of hair. the application to the short, even hairstyle, attested from the late 17th century, visually captures the notion of hair ending in a blunt, bouncing line.
Analysis
this word is considered a simplex form. it is likely of onomatopoeic or expressive origin, imitating the sound or motion of a light, bouncing impact.
Examples
the small boat bobbed gently on the waves.
she decided to get a bob for the summer.
he gave a quick bob of his head in acknowledgement.