Select the INCORRECTLY spelt word.

The correct option/answer is "Dissapear".

Let us analyze the spelling of each option provided to identify the incorrectly spelt word:

1. Entrepreneur: This is spelled correctly. An entrepreneur is a person who sets up a business or businesses, taking on financial risks in the hope of profit.
2. Supersede: This is spelled correctly. It means to take the place of a person or thing previously in authority or use. Note the "sede" ending, which is a common spelling trap (often confused with "cede").
3. Dissapear: This is incorrectly spelt. The correct spelling is "Disappear" (with one 's' and two 'p's). The word is formed by adding the prefix dis- to the root word appear (dis + appear = disappear).
4. Vicinity: This is spelled correctly. It refers to the area near or surrounding a particular place.

Therefore, the word with the incorrect spelling is "Dissapear".