To bob is to dip up and down, the way something does when it floats on the surface of water. A lobster buoy bobs in the ocean, marking the spot where a lobsterman's trap is set.

Your friend stands out when her red hat bobs among a crowd of people, and so does a red boat as it bobs on a lake. You might bob your head to indicate agreement or get a short haircut that's also called a bob. The motion bob comes from the Old English bobben, "to strike," while the hair style stems from the earlier bobbe, or "cluster," and first referred a trimmed horse's tail.

Definitions of bob
  1. verb
    move up and down repeatedly
    “her rucksack bobbed gently on her back”
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    bob forward and under so as to feed off the bottom of a body of water
    bob about, bob around
    move up and down with no specific path
    type of:
    move so as to change position, perform a nontranslational motion
  2. verb
    make a curtsy; usually done only by girls and women; as a sign of respect
    synonyms: curtsy
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    type of:
    greet, recognise, recognize
    express greetings upon meeting someone
  3. noun
    a short abrupt inclination (as of the head)
    “he gave me a short bob of acknowledgement”
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    type of:
    inclination, inclining
    the act of inclining; bending forward
  4. noun
    a hair style for women and children; a short haircut all around
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    type of:
    coif, coiffure, hair style, hairdo, hairstyle
    the arrangement of the hair (especially a woman's hair)
  5. noun
    a short or shortened tail of certain animals
    synonyms: bobtail, dock
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    type of:
    the posterior part of the body of a vertebrate especially when elongated and extending beyond the trunk or main part of the body
  6. verb
    remove or shorten the tail of an animal
    synonyms: dock, tail
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    type of:
    separate with or as if with an instrument
  7. verb
    cut hair in the style of a bob
    “Bernice bobs her hair these days!”
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    type of:
    arrange, coif, coiffe, coiffure, do, dress, set
    arrange attractively
  8. noun
    a long racing sled (for 2 or more people) with a steering mechanism
    synonyms: bobsled, bobsleigh
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    type of:
    sled, sledge, sleigh
    a vehicle mounted on runners and pulled by horses or dogs; for transportation over snow
  9. verb
    ride a bobsled
    “The boys bobbed down the hill screaming with pleasure”
    synonyms: bobsled
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    type of:
    sled, sleigh
    ride (on) a sled
  10. noun
    a former monetary unit in Great Britain
    synonyms: British shilling, shilling
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    type of:
    British monetary unit
    monetary unit in Great Britain
  11. noun
    a hanging weight, especially a metal ball on a string
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    kite tail
    a bob on a kite to provide balance
    plumb, plumb bob, plummet
    the metal bob of a plumb line
    sounding lead
    a metal bob at the end of a sounding line
    type of:
    an artifact that is heavy
  12. noun
    a small float usually made of cork; attached to a fishing line
    synonyms: bobber, bobfloat, cork
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    type of:
    something that floats on the surface of water
Word Family

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