n.

1. a former monetary unit in Great Britain;
   British shilling, shilling
2. a hair style for women and children; a short haircut all around
3. a long racing sled (for 2 or more people) with a steering mechanism;
   bobsled, bobsleigh
4. a hanging weight, especially a metal ball on a string
5. a small float usually made of cork; attached to a fishing line;
   bobber, cork, bobfloat
6. a short or shortened tail of certain animals;
   bobtail, dock
7. a short abrupt inclination (as of the head)
   
   • he gave me a short bob of acknowledgement

v.

1. move up and down repeatedly
   
   • her rucksack bobbed gently on her back
2. ride a bobsled;
   bobsled
   
   • The boys bobbed down the hill screaming with pleasure
3. remove or shorten the tail of an animal;
   dock, tail
4. make a curtsy; usually done only by girls and women; as a sign of respect;
   curtsy
   
   • She curtsied when she shook the Queen's hand
5. cut hair in the style of a bob
   
   • Bernice bobs her hair these days!