きしゅう
きしゅう 【奇習 】a strange custom .
きしゅう 【奇襲 】〘make 〙 a surprise [⦅やや話 ⦆ a sneak ] attack ⦅on ⦆.
きしゅう 【既習 】▸ 既習単語 a word one has already learned [studied ]. (↔ 未習 )