An archaic or rare form meaning forceful, stressed, or expressed with strong emotion or conviction; relating to emphasis.
From emphatic + -al (adjectival suffix), though emphatic itself was already an adjective. The -al variant emerged but never achieved widespread use compared to emphatic.
Language is full of failed experiments—emphatical was a perfectly logical attempt to form an adjective, but emphatic already worked so well that the new version never caught on.
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