1. comparative form of extreme; more extreme in degree, intensity, or character
Usage: Less common than 'more extreme' in modern usage; often considered nonstandard or archaic

Examples

• The weather this year has been extremer than last year.
• His views became extremer as he grew older.
• The extremer end of the political spectrum rarely wins mainstream support.
• She took an extremer approach to solving the problem.
• The extremer temperatures in the desert make survival difficult.