Word-A-Week in Indo-European
Today's Word: *kwel-
Translation:  a wheel, round
Cognates (32): Greek polos (a round axis) - remember *kw becomes Greek p before o, a, u
  Latin colere (to cultivate, move around), bucolicus (a cattleman) = bou- (a bull) + col-
  Common Celtic *kol- (to move around), bowkolos (a cattleman); > 
Old Irish bochaill (a herdsman), Irish & Scottish Gaelic buachaill, Welsh bugail, Cornish & Breton bugel
Sanskrit carati (he moves, wanders)
Avestan c'axra (a chariot, a wagon)
Tocharian kuka"l (a wagon)
  Common Germanic *hwel-, > 
Old Norse hvel (a wheel), Old English hweol, > 
English wheel, Swedish hjul
  Common Baltic *kel- (a wheel), > 
Old Prussian & Sudovian kelan (a wheel; neut.), Lithuanian kelias (a road, a way)
  Common Slavic *kolo (a wheel), > 
Ukrainian & Old Russian & Serbo-Croatian & Slovene & Czech & Slovak & Polish & Sorbian kolo, Lower Sorbian kolaso, Russian koleso (a wheel)
Notes: Via the Latin word colere (to cultivate land) this stem then gave the term cultura (culture) which exists in every European language. The traces of this stem in so many Indo-European branches not only shows its ancient origin, but also proves the fact that Proto-Indo-Europeans knew the wheel before the community broke up. Now we can check when the wheel was invented in Mesopotamia, and state that the breakup of the Indo-European community happened several centuries after this time.