*kent

 
D.Q. Adams, in Encyclopedia of Indo-European Culture notes under *kéntr/n-  that the word means 'patches', 'patched clothing'. He speculates this is related to *kent, in that ancient clothing, particularly animal skins, would have been stitched together, i.e., 'pricked' with a needle. He also notes Latvian sits, 'hunting spear'. (My goodness! I'm seeing the kentum/satem isogloss here for myself for the first time! (p. 110).

The entry for *kent ( by Joe Salmons and Mary Niepokuj, pp. 509-10) gives 'sharp' as the main sense. This is related to Old Norse hannar (<*hanþaraz) 'clever', Old High German handeg  'bitter, stern', Gothic handugs  'wise', Latvian sits  'hunting spear'. They say "the connection between the German and Greek forms is uncertain. The variant *keneth2- (k is circumflex) is seen in Avestan snath (th = theta) 'stab'. Widespread and old in IE."

I think the underlying semantic space is best expressed by "to prick, poke or jab with a sharp-pointed device".