# casing

/ˈkeɪsɪŋ/ (US) · /kˈeɪsɪŋ/ (UK)

Source: https://englishreference.com/word/casing
Updated: 2026-08-08

## Senses

### 1. outer covering

noun · CEFR B2

a protective outer layer or shell that covers an object.

For teachers: an outer cover or shell designed to protect or contain an object.

- The plastic casing of the phone was cracked after it fell on the floor.
- The engineer removed the outer casing of the turbine to inspect the internal blades for signs of thermal fatigue.

### 2. window or door frame

noun · CEFR C1 · Technical

the decorative wooden or metal frame around a door or window.

For teachers: the decorative trim or moulding that surrounds a door or window opening.

- We painted the window casing white to match the rest of the room.
- The restoration project required custom-milled oak casing to match the original Victorian architectural details of the drawing room.

### 3. sausage skin

noun · CEFR C1 · Technical

the thin outer layer that holds the meat inside a sausage.

For teachers: the material, either natural or synthetic, used to enclose the filling of a sausage.

- The chef used natural casings to make the traditional pork sausages.
- Artisanal butchers often prefer natural sheep casings for their superior texture and snap compared to collagen alternatives.

### 4. letter case

noun · CEFR C1 · Technical

the use of capital or small letters in a piece of text.

For teachers: the collective state or arrangement of uppercase and lowercase letters within a string or document.

- The software automatically corrects the casing of your sentences.
- The script failed because the database was sensitive to casing, and the input string contained an unexpected capital letter.

### 5. looking around a place

verb · CEFR B2 · Informal

looking at a building carefully, usually to plan a crime like a robbery.

For teachers: the act of observing a location or building surreptitiously, typically to plan a burglary or other crime.

- The police caught the men while they were casing the jewelry store.
- The security footage showed a suspicious vehicle casing the warehouse for several nights before the attempted break-in.

Usage: Often used in the phrase 'casing the joint'.

Teaching tip: This is a very specific use found mostly in crime fiction and police dramas.

## Examples

- The phone has a plastic casing.
- The technician replaced the broken casing on the laptop to protect the internal components.
- The architect chose a stone casing for the windows to match the historic façade of the building.

---

From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.