みちすう 未知数 Common word LinksSentence search for 未知数Sentence search for みちすうKanji details for 未, 知 and 数Edit in JMdict Noun1. (an) unknown; unknown number; variableMathematics, See also 既知数Noun, Noun which may take the genitive case particle 'no'2. unknown quantity; not yet known Discussions Log in to talk about this word.