Literally: other – say – no – use
Alternately: “Don’t talk about this to anyone.” “Loose lips sink ships.”
Notes: 言 may also be pronounced gen.
In contrast to the aphoristic nature of most yojijukugo, this one is a direct imperative – a trait it shares with other phrases ending in 無用.
The rabbit’s name is Shouta (翔太)? Don’t tell anyone, though.
I love the written word more than anything else I've had the chance to work with. I'm back in the States from Japan for grad school, but still studying Japanese with the hope of becoming a translator -- or writer, or even teacher -- as long as it's something language-related.