sleep tight

Etymology
The word is sometimes explained as here meaning “well, soundly”. However, it can just as well be interpreted in its literal sense of “firm, fast”; compare.

Phrase

 * 1) If you keep yourself tightly bundled you will sleep warm and rest well.

Translations

 * Catalan: dorm bé
 * Dutch:, , , trusten, truste
 * French: dors bien, dormez bien
 * German: schlaf gut (informal), schlafen Sie gut (formal)
 * Italian: dormi bene
 * Lao:
 * Polish: dobranoc, pchły na noc
 * Portuguese: durma bem
 * Spanish:, duerma bien
 * Swedish: