音信不通(おんしんふつう)

A 四字熟語(よじじゅくご) (four-character compound) meaning complete loss of contact with someone.

Compound: 音信(おんしん) (news/correspondence) + 不通(ふつう) (not going through)

Common collocations

• 音信不通(おんしんふつう)になる: to lose contact
• 音信不通(おんしんふつう)のまま: still out of touch
• 長年(ながねん)音信不通(おんしんふつう)だった: had been out of touch for years
• 音信不通(おんしんふつう)だった人(ひと)から連絡(れんらく)が来(く)る: to hear from someone who had been out of touch

Usage

Can describe both intentional disappearance (someone cuts off contact) and unintentional loss of contact (drifting apart). Often used in the pattern ～以来(いらい)音信不通(おんしんふつう)だ (have been out of touch since ~).

In modern Japanese, also used casually for someone who stops responding to messages or calls.