To miss the opportunity to go someplace; to fail to go as planned (often due to circumstances or forgetfulness).
忙しくて両親の家に行きそびれてしまった。
I was so busy that I never got around to visiting my parents' house.
セールに行こうと思っていたが、予定が入り行きそびれた。
I planned to go to the sale, but my schedule changed and I missed the chance.
せっかくの桜の季節に外出するタイミングを逃して行きそびれた。
I missed the timing to go out during the cherry-blossom season and couldn't go.