Hush-hush and Laconism

Hush-hush adjective - Not known or meant to be known by the general populace.

Laconism and hush-hush are semantically related In some cases you can use "Laconism" instead a noun phrase "Hush-hush".

Laconism noun - Terseness of expression.

Hush-hush and laconism are semantically related in speech topic. Sometimes you can use "Hush-hush" instead a noun "Laconism", if it concerns topics such as silence.