Proto-Indo-European Roots

Root/Stem: *skel-
Meaning:  to chop
Cognates:
Hellenic Greek skalló 'I dig'
Italic Latin culter 'knife'
Celtic Common Celtic *skal- 'to chop, to split' >
Scottish sgoltadh 'splitting', Irish & Middle Irish scoiltim 'I split', Old Irish siuscoilt, Welsh chwalu, Cornish scullye, Breton skul'a
Indic Sanskrit kal√° 'a small part'
Anatolian Hittite iškallai- 'to cut, to tear'
Armenian Armenian celk`em 'I chop, I break'
Germanic Gothic skilja 'butcher'
Baltic Lithuanian skeliu 'I chop', Latvian sk,elt 'to chop'
Slavic Common Slavic *skala 'rock', *kolti 'to chop' >
Russian skala 'rock', kolot' 'to chop'
Notes: The phonetics of the root is very interesting for its 's-mobile' which disappears in Indic, Italic and takes a strange reflection in Armenian. It is even more strange to compare it with an omonymic root *skel- 'to stumble' which has the following cognates: Indic skhalate, Armenian sxalem
The glottalic theory suggests the initial *s- here was in fact a palatalized sound *s', different from *s which has always been attested as the only spirant in Indo-European.