Definition of "Bob" :
noun: a short abrupt inclination (as of the head)
"He gave me a short bob of acknowledgement."
noun: a short or shortened tail of certain animals
noun: a small float usually made of cork; attached to a fishing line
noun: a hanging weight, especially a metal ball on a string
noun: a long racing sled (for 2 or more people) with a steering mechanism
noun: a hair style for women and children; a short haircut all around
noun: a former monetary unit in Great Britain
verb: cut hair in the style of a bob
"Bernice bobs her hair these days!."
verb: make a curtsy; usually done only by girls and women; as a sign of respect
verb: remove or shorten the tail of an animal
verb: move up and down repeatedly
"Her rucksack bobbed gently on her back."
verb: ride a bobsled
"The boys bobbed down the hill screaming with pleasure."