"casings" in the noun sense
1. shell, case, casing
the housing or outer covering of something
"the clock has a walnut case"
2. casing
the outermost covering of a pneumatic tire
3. casing, case
the enclosing frame around a door or window opening
"the casings had rotted away and had to be replaced"
Source: WordNet® (An amazing lexical database of English)
Princeton University "About WordNet®."
WordNet®. Princeton University. 2010.
View WordNet® License