Negative adverb used before verbs, adjectives, and other adverbs to indicate negation; also used as a bound-form prefix to form terms with opposite meanings

to collide; to run into; to strike; to hit a surface forcefully

south; southern; directional cardinal point opposite to 北 běi

a wall or similar barrier built of brick, stone, or other materials

Negative adverb used before verbs, adjectives, and other adverbs to indicate negation; also used as a bound-form prefix to form terms with opposite meanings

To come back; to return to a previous place or to a previous point in a task to do it again