Comparative form of extreme; more extreme or going further toward the greatest degree of intensity or distance from the center.
From extreme + -er (comparative suffix). While 'more extreme' is preferred in modern English, 'extremer' follows the standard Old English comparative pattern.
Most native speakers say 'more extreme' rather than 'extremer,' but both are technically correct—it's a reminder that English is messy because it inherited two comparison systems when Germanic and Latin influences merged!
Complete word intelligence in one call. Free tier — 50 lookups/day.