蹭 sang³ {cèng}

1. to rub against
2. to walk slowly
3. to freeload (colloquial)

蹭蹬 sang³ dang⁶ {cèng dèng}

1. to have bad luck
2. dammit!

蹭吃 sang³ hek³ {cèng chī}

to freeload for food

蹭吃蹭喝 sang³ hek³ sang³ hot³ {cèng chī cèng hē}

to cadge a meal