To profane or desecrate something sacred; to treat something holy as unholy.
From 'dis-' (reversing) plus 'hallow' (from Old English 'halgian' meaning to make holy, root of 'holy'). The prefix reverses the sanctification.
This archaic word reveals the depth of English's sacred vocabulary—'hallow,' 'holy,' 'hallowed' (as in the Lord's Prayer) all stem from the same root, and 'dishallow' shows how negation prefixes could work with any verb in Middle English.
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