trench vs natural depression

trench and natural depression both are nouns.

Word	Noun	Adjective	Verb	Adverb
trench	Yes	No	Yes	No
natural depression	Yes	No	No	No

As nouns, natural depression is a hypernym of trench; that is, natural depression is a word with a broader meaning than trench:

Other hypernyms of trench include depression.

trench (noun)	natural depression (noun)
a ditch dug as a fortification having a parapet of the excavated earth	a sunken or depressed geological formation
any long ditch cut in the ground
a long steep-sided depression in the ocean floor

trench (verb)	natural depression (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