Select the INCORRECTLY spelt word.

disapprooval

The incorrectly spelled word is "disapprooval" (Option 4).

Explanation of all options:

1. Orientation: Correctly spelled. It refers to the process of familiarizing or adapting to a new situation, environment, or role.

2. Corroborate: Correctly spelled. It means to confirm, support, or give evidence for a statement, theory, or claim.

3. Disappointment: Correctly spelled. It represents the feeling of sadness, dissatisfaction, or letdown when expectations are not met.

4. Disapprooval: Incorrectly spelled. The correct spelling is "disapproval." It denotes the act of expressing or feeling disapproval or disagreement.