bob (v.1)youdaoicibaDictYouDict
"move with a short, jerking motion," late 14c., probably connected to Middle English bobben "to strike, beat" (late 13c.), perhaps of echoic origin. Another early sense was "to make a fool of, cheat" (early 14c.). Related: Bobbed; bobbing. The sense in bobbing for apples (or cherries) recorded by 1799.
hitch (v.)youdaoicibaDictYouDict
mid-15c., probably from Middle English icchen "to move as with a jerk, to stir" (c. 1200). It lacks cognates in other languages. The connection with icchen may be in notion of "hitching up" pants or boots with a jerking motion. Sense of "become fastened," especially by a hook, first recorded 1570s, originally nautical. Meaning "to marry" is from 1844 (to hitch horses together "get along well," especially of married couples, is from 1837, American English). Short for hitchhike (v.) by 1931. Related: Hitched; hitching.
HottentotyoudaoicibaDictYouDict
1670s, from S.African Dutch, said to mean "stammerer," it is from hot en tot "hot and tot," nonsense words imitative of the clicking, jerking Khoisan speech.
jerk (v.1)youdaoicibaDictYouDict
"to pull," 1540s, "to lash, strike as with a whip," of uncertain origin, perhaps echoic. Related: Jerked; jerking.