Some common reasons include: 1  a serious accident â such as a road accident, a severe head injury, a serious fall or severe burns. 2  a serious short-term condition â such as a heart attack or a stroke. 3  a serious infection â such as sepsis (blood poisoning) or severe pneumonia.
The definition of unnecessary is not needed. An example of something unnecessary is a bowl of sugar for cooking meatballs.
1. an insufficiency, shortage, or absence of something required or desired. 2. something that is required but is absent or in short supply. vb. (when: intr, often foll by in or for) to be deficient (in) or have need (of): to lack purpose.