Probably a back-formation from polysemantic. <span class="searchmatch">polysemant</span> (plural <span class="searchmatch">polysemants</span>) A word or phrase with more than one meaning....
<span class="searchmatch">polysemants</span> plural of <span class="searchmatch">polysemant</span>...
Borrowed from French polysémantisme. polisemantism n (uncountable) <span class="searchmatch">polysemantism</span>...