Other forms: slits, slitting
To slit something is to cut it open along one long, narrow line. You slit an envelope across the top with a thumbnail, slit the film on a tray of chicken, slit a taped box down the middle.
The noun is the cut itself, or any narrow gap shaped like one: the slit in a letterbox, the slit up the side of a skirt, the slit of light under a closed door. Slit stays slit in the past — you slit it yesterday, never slitted. It has a nasty edge in a few fixed uses: slit someone's throat, slit your wrists. And a slit runs lengthways; a short chop across is a cut or a slash.
1verbslitTo cut a long, narrow opening in or along something.
“He slit the envelope open with a thumbnail.”
synonyms: slash, cut open
2nounlongA long, narrow cut or opening.
“A slit in the curtains let a line of light onto the floor.”
slit is a kind of cut.
Slit comes down from Old English slītan, from Proto-Germanic *slītaną, 'to tear apart', and behind that a Proto-Indo-European root *(s)leyd- meaning to tear or split apart. The old sense was rougher than today's neat line — something rent open rather than sliced. It is related to slice, which reached English later through French.
Proto-Indo-European
*(s)leyd- — to tear, rend (cut apart), split apart
Proto-Germanic
*slītaną — to tear apart
Old English
slītan
Middle English
slitten
English, today
slit
From Middle English slitten, from Old English slītan, from Proto-Germanic slītaną (“to tear apart”), from Proto-Indo-European (s)leyd- (“to tear, rend (cut apart), split apart”). Possibly cognate with Latin laedo (“to strike, hurt, injure”). a doublet of slite; also related to slice through French borrowing. Apparently unrelated to slot, whose etymology, however, is uncertain.
Etymology from Wiktionary, CC BY-SA