プログレッシブ和英中辞典(第4版)の解説
ぶさた【無沙汰】
ごぶさたをおわび申し上げます
I apologize for my long silence./I'm sorry I haven't contacted you for such a long time.
ごぶさたしました
〔手紙で〕Excuse me for not writing for such a long time./〔久し振りで会って〕It's been ages [a long time] since I saw you last.
あの店にもずいぶんごぶさたしている
I haven't been to that shop for a long time.