Here are some examples of words starting with these prefixes:
Uni-
* Unicycle: A vehicle with one wheel.
* Unicorn: A mythical creature with one horn.
* Unilateral: Affecting only one side.
* Unify: To make into one.
* Unique: Being the only one of its kind.
Mono-
* Monotone: A single, unchanging tone.
* Monopoly: Exclusive control of a commodity or service.
* Monotony: The state of being boring and unchanging.
* Monorail: A railway with one rail.
* Monocle: A single eyeglass.
Let me know if you'd like to explore more words with these prefixes!