monstro-, monstr-, mone-, monu-, moni-

(Latin: monere, to warn; to remind, to advise, to instruct)

Quod erat demonstrandum, Q.E.D., QED
Which was the thing to be demonstrated; Which was to be demonstrated.

A formula appended at the end of a proof in geometry, or other mathematical solution, with the meaning, "We have proven the proposition we set out to prove."

undemonstrable (adjective)
1. Not capable of fuller evidence.
2. Incapable of showing or presenting.
undemonstrative (adjective)
1. Not open to exhibition or expression of emotion; especially, of affection.
2. Restrained or a tendency not to show emotions openly.
3. Not disposed to expressions of one's feelings; reserved.
undemonstratively (adverb)
A reference to someone who can't, or won't, show his or her emotions.