Demonstrate, v. t. — Webster enters it under “demonstrate”
Etymology: [L. demonstratus, p. p. of demonstrare to demonstrate; de- + monstrare to show. See Monster.]
1. To point out; to show; to exhibit; to make evident. Shak.
2. To show, or make evident, by reasoning or proof; to prove by deduction; to establish so as to exclude the possibility of doubt or denial. We can not demonstrate these things so as to show that the contrary often involves a contradiction. Tillotson.
3. (Anat.)
To exhibit and explain (a dissection or other anatomical preparation).
Shades of meaning
Fernald lists demonstrated only as an antonym, under absurd.
Where he writes about it:
That which has been either demonstrated or proved so as to secure general acceptance is said to be established. — from reason
Synonyms
none given