- 无 無 adjectiveverbto not haveto not have; there is no; lack; (as prefix) non-; un-; -less
- 孔 nounholehole; aperture; opening
- 不 adverbnotNegative adverb used before verbs, adjectives, and other adverbs to indicate negation; also used as a bound-form prefix to form terms with opposite meanings
- 钻 鑽 verbto drillto drill or bore a hole by rotating a pointed tool