bob

Etymology 1

From Middle English bobben (“to strike, beat, shake, jog”), of uncertain origin. Compare Scots bob (“to mark, dance with a bobbing motion”), Icelandic boppa (“to wave up and down”), Swedish bobba (“to bob”), Dutch dobberen ("bobbing").

verb

1. (intransitive) To move gently and vertically, in either a single motion or repeatedly up and down, at or near the surface of a body of water, or similar medium.
   The cork bobbed gently in the calm water.
   The ball, which we had thought lost, suddenly bobbed up out of the water.
   The flowers were bobbing in the wind.
2. (transitive) To move (something) as though it were bobbing in water.
   I bobbed my head underwater and saw the goldfish.
   bob one's head (= to nod)
3. To curtsy.
4. To strike with a quick, light blow; to tap.
   He was suddenly bobbed on the face by the servants. 1533, Thomas Elyot, The Book of the Governor
5. (intransitive) Synonym of blob (“catch eels using worms strung on thread”)
   After they had had supper Frank said, Do you remember those men whom we saw near Norwich, who sat in small boats all the night long, and with a line in each hand, bobbed for eels? 1876, George Christopher Davies, The Swan and Her Crew, page 134

noun

1. A bobbing motion; a quick up and down movement.
   a bob of the head
2. A curtsy.
3. A bobber (buoyant fishing device).
   Or yellow bobs turn'd up before the plough / Are chiefest baits, with cork and lead enough. 1613, John Dennys, The Secrets of Angling
4. Any of various hesperiid butterflies.

Etymology 2

From Middle English bobbe (“a cluster (of fruit); a twig with its leaves, a spray”).

noun

1. A bob haircut.
2. Any round object attached loosely to a flexible line, a rod, a body part etc., so that it may swing when hanging from it.
   Ecod! I have got them. Here they are. My cousin Con's necklaces, bobs and all. 1773, Oliver Goldsmith, She Stoops to Conquer
3. The dangling mass of a pendulum or plumb line.
4. The docked tail of a horse.
5. A short line ending a stanza of a poem.
6. The short runner of a sled.
7. A bobsleigh.
8. A small wheel, made of leather, with rounded edges, used in polishing spoons, etc.
9. A working beam in a steam engine.
10. A particular style of ringing changes on bells.
11. A blow; a shake or jog; a rap, as with the fist.
12. (obsolete) A knot or short curl of hair; also, a bob wig.
    A plain brown bob he wore. 1737, William Shenstone, The Extent of Cookery
13. (obsolete) The refrain of a song.
14. (obsolete) A jeer; a sharp jest or taunt.

verb

1. (transitive) To cut (hair) into a bob haircut.
   I got my hair bobbed. How do you like it?
2. (transitive) To shorten by cutting; to dock; to crop.
3. To bobsleigh.

Etymology 3

noun

1. (Kenya, slang; UK and Australia, historical, dated) A shilling.
   […] there was a sound of barking and a great hefty dog of the Hound of the Baskervilles type came galloping at me, obviously intent on mayhem, [... and] I was just commending my soul to God and thinking that this was where my new flannel trousers got about thirty bobs' worth of value bitten out of them […] 1960, P. G. Wodehouse, chapter XVII, in Jeeves in the Offing
2. (Australia, dated slang) A 10-cent coin.
3. (slang) An unspecified amount of money.
   Spot me a few bob, Robert.
   I could have saved myself a few bob buying it somewhere else.

Etymology 4

noun

1. Abbreviation of shishkabob.

Etymology 5

blitter object

noun

1. (computer graphics, demoscene) A graphical element, resembling a hardware sprite, that can be blitted around the screen in large numbers.
   The bob list determines the drawing priority […] 1986, Eugene P Mortimore, Amiga programmer's handbook, Volumes 1-2
   IMHO, youd be better doing other things with the CPU and letting the blitter draw bobs, esp on a machine with fast ram. 1995, John Girvin, “Blitting bobs”, in comp.sys.amiga.programmer (Usenet)
   Changes: This release adds 2 new effects (bobs and unlimited bobs), has a GFX directory for sharing graphics, adds utility functions to the common code 2002, demoeffects, “Demotized 0.0.1 - A collection of demo effects from the early days of the demo scene.”, in fm.announce (Usenet)