12) antipodes. Roget s II: The New Thesaurus, Third Edition. 1995.
...That which is diametrically opposed to another: antipode, antithesis, antonym, contrary, converse2, counter, opposite, reverse. Logic : contradictory, contrapositive....

13) antipode. Roget s II: The New Thesaurus, Third Edition. 1995.
...That which is diametrically opposed to another: antipodes, antithesis, antonym, contrary, converse2, counter, opposite, reverse. Logic : contradictory, contrapositive....

14) opposite. Roget s II: The New Thesaurus, Third Edition. 1995.
...That which is diametrically opposed to another: antipode, antipodes, antithesis, antonym, contrary, converse2, counter, reverse. Logic : contradictory, contrapositive....

15) antithesis. Roget s II: The New Thesaurus, Third Edition. 1995.
...1. That which is diametrically opposed to another: antipode, antipodes, antonym, contrary, converse2, counter, opposite, reverse. Logic : contradictory, contrapositive....

16) reverse. Roget s II: The New Thesaurus, Third Edition. 1995.
...1. That which is diametrically opposed to another: antipode, antipodes, antithesis, antonym, contrary, converse2, counter, opposite. Logic : contradictory, contrapositive....

17) contradictory. Roget s II: The New Thesaurus, Third Edition. 1995.
...Logic. That which is diametrically opposed to another: antipode, antipodes, antithesis, antonym, contrary, converse2, counter, opposite, reverse. Logic : contrapositive....

18) contrapositive. Roget s II: The New Thesaurus, Third Edition. 1995.
...Logic. That which is diametrically opposed to another: antipode, antipodes, antithesis, antonym, contrary, converse2, counter, opposite, reverse. Logic : contradictory....

19) contrary. Roget s II: The New Thesaurus, Third Edition. 1995.
...That which is diametrically opposed to another: antipode, antipodes, antithesis, antonym, converse2, counter, opposite, reverse. Logic : contradictory, contrapositive....

20) artificial, counterfeit, ersatz, fake, false, imitation, sham, spurious, substitute, synthetic. The Columbia Guide to Standard American English. 1993
...The number of these synonyms in English is very great. Artificial is the antonym of natural and real and usually indicates something man-made, in imitation of something...