slit

nouns

a long narrow opening
is a type of (narrower)
a vacant or unobstructed space that is man-made
"they left a small opening for the cat at the bottom of the door"
obscene terms for female genitals
a depression scratched or carved into a surface
a narrow fissure
is a type of (narrower)
a long narrow opening

verbs

make a clean cut through
"slit her throat"
cut a slit into
"slit the throat of the victim"
is a type of (narrower)
make an incision into by carving or cutting