sker-
“to cut, separate”Source of English shear, share, short, shirt, skirt
Root meaning to cut, yielding a large family including shear, share, short, score, and Latin curtus.
Discussion
The Proto-Indo-European root *sker- meant "to cut, to separate, to divide" and is among the most productive roots in the entire reconstructed lexicon, generating an enormous family of words across all major branches. The basic action of cutting — one of the earliest and most essential human technologies — naturally lent itself to extensive metaphorical development.
In Germanic, the initial *sk- was retained (Grimm's Law affected stops, not fricatives), and the root produced a remarkable cluster of English words. Shear (to cut), short (cut down), score (a cut or notch, hence a tally), shirt and skirt (both originally "a cut piece" of cloth — the same word, with shirt from Old English and skirt from Old Norse), shard (a broken/cut piece), and share (a cut portion) all descend from this root. The word sharp may also be connected, as "that which cuts".
The doublet shirt and skirt is particularly instructive: both derive from the same Proto-Germanic form *skurtijō "a short garment", but shirt entered English through Old English scyrte while skirt was borrowed from Old Norse skyrta. The semantic split — shirt for the upper body, skirt for the lower — occurred after the words had diverged phonologically.
Latin curtus "shortened, cut short" (the source of English curt, curtail, and the name Curtis) is a cognate. Greek keirein "to cut" produced English caret (a cutting mark), and the Latin-Greek hybrid carnage derives from a related root concerning the cutting of flesh.
The semantic range of *sker- — cutting, shortening, scoring, sharing, clothing — reveals how the physical act of cutting pervaded Proto-Indo-European material culture. Textiles were cut to make garments, tallies were scored on sticks for counting, portions were cut for distribution, and land was divided among the community. The root *sker- is a lexical archaeology of daily life in the proto-language community.