► 動詞遡及  [そきゅう]  [
遡及する]    
meaning:  go back  rank: 4☆ 
刑事法は遡及しない ⇨ Criminal laws are not retroactive
► 名詞遡及  [そきゅう]    
meaning:  go back  rank: 4☆ 
刑罰法規不遡及の
原則 ⇨ The principle of no retroactive application of criminal laws
More examples:- 法律の効力は遡及しない ⇨ The effect of the law is not retroactive