adj.1550s, from Latin immemorabilis, from assimilated form of in- "not" (see in- (1)) + memorabilis (see memorable). if (window.googletag) {googletag.cmd.push(function() { googletag.display('dcomMobileSERPDisplayTopAd-300x250'); });} else {console.error('googletag not defined, dcomMobileSERPDisplayTopAd-300x250');}