undermine

As verbs the difference between undermine and reduce

is that undermine is to dig underneath (something), to make a passage or for destructive or military purposes; to sap while reduce is to bring down the size, quantity, quality, value or intensity of something; to diminish, to lower, to impair.

As a noun erosion

is the result of having been being worn away or eroded, as by a glacier on rock or the sea on a cliff face.

As a verb undermine is

to dig underneath (something), to make a passage or for destructive or military purposes; to sap.

As verbs the difference between undermine and underdig

is that undermine is to dig underneath (something), to make a passage or for destructive or military purposes; to sap while underdig is (obsolete) to dig under or beneath; to undermine.

As a verb undermine

is to dig underneath (something), to make a passage or for destructive or military purposes; to sap.

As an adjective antipositional is

(chess|bridge) tending to undermine or harm one's position.

As a verb undermine

is to dig underneath (something), to make a passage or for destructive or military purposes; to sap.

As a noun underminer is

one who undermines.