casing

noun

1. That which encloses or encases.

   “Some people like to split the casing of a sausage before cooking so it doesn’t burst.”

   “And, by your leave, for all the marvellous rich and sumptuous coat a weareth, he is very like a false jewel in a rich casing.”

   “It was expected that the whole of the "3700" and "3900" classes would be so treated, but it was found that the streamlined casing caused the engines to run hot on express work and they were relegated to goods trains; the casings were removed during the war.”

2. The decorative trim around a door or window.
3. A metal pipe used to line the borehole of a well.
4. (uncountable)The state of letter case across a whole phrase or whole lines of text; the collective state/arrangement of uppercase and lowercase letters.

   “The replacement string should have the same casing as the matched text.”

5. (Appalachia, dated)A tire.

verb

1. (form-of, gerund, participle, present)present participle and gerund of case