Added 9 October 2026 casing /ˈkeɪsɪŋ/ noun Categories: ThingsRare Words noun ! Definition from WordNet 3.1, Princeton University. Pronunciation from Wiktionary, via Kaikki.org. More about casing at Wordnik → Where our words come from → The housing or outer covering of something. the clock has a walnut case The outermost covering of a pneumatic tire. The enclosing frame around a door or window opening. the casings had rotted away and had to be replaced Related Words: shellwrapperenveloplinerliningcovershroudgirdleenclosurepackageboxbezel Back to today's word