trench vs excavate

trench is a noun but excavate is not a noun.

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

As verbs, excavate is a hypernym of trench; that is, excavate is a word with a broader meaning than trench:

Other hypernyms of trench include dig, hollow.

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

trench (verb)	excavate (verb)
cut or carve deeply into	find by digging in the ground
dig a trench or trenches	remove the inner part or the core of
cut a trench in, as for drainage	form by hollowing
fortify by surrounding with trenches	recover through digging
set, plant, or bury in a trench
impinge or infringe upon