odd unique strange abnormal
antonym
The direct antonym applicable for the term normal is abnormal.
common
Different, or a change. extraordinary. special, unique
That would be "common".
"Normal" or "Habitual"is the antonym of unconventional.
Un unique different
From a chemical perspective, the antonym is oxidation In normal conversation, an antonym could be "enlargement"
Normal
normal.
Usual, common, etc ....