Uniform

the same all the way through; consistent (adj)

Unison

One voice (n)

Unanimous

Showing complete agreement (adj)

Monologue

A speech made by a single person (n)

Monopolize

To use or take so as to prevent others from using or taking (v)

Monogamy

Married to only one person at a time (n)

Monolithic

Exactly the same throughout; lacking any diversity (adj)

Homonym

A word spelled exactly like another word, but having a different meaning (n)

Homogenized

Forced to be exactly the same (adj)

Equitable

Fair; just (adj)

Equilibrium

Balance; steadiness (n)

Iniquity

An injustice; a wrong or wicked action or situation (n)

UNI

Latin: UNUS

One (root)

MONO

Greek: MONOS

One (root)

HOMO

Greek: HOMOS

The same (root)

EQUI

Latin: AEQUUS

Equal, even (root)