trench vs slit trench

trench and slit trench both are nouns.

Word	Noun	Adjective	Verb	Adverb
trench	Yes	No	Yes	No
slit trench	Yes	No	No	No

As nouns, slit trench is a hyponym of trench; that is, slit trench is a word with a more specific, narrower meaning than trench:

trench: a ditch dug as a fortification having a parapet of the excavated earth
slit trench: narrow trench for shelter in battle

Other hyponyms of trench include approach trench, communication trench, fire trench, fosse, moat.

trench (noun)	slit trench (noun)
a ditch dug as a fortification having a parapet of the excavated earth	narrow trench for shelter in battle
any long ditch cut in the ground
a long steep-sided depression in the ocean floor

trench (verb)	slit trench (verb)
cut or carve deeply into
dig a trench or trenches
cut a trench in, as for drainage
fortify by surrounding with trenches
set, plant, or bury in a trench
impinge or infringe upon