Select the INCORRECTLY spelt word.

Recalcitrent

The incorrectly spelt word in the given options is "Recalcitrent." The correct spelling is "Recalcitrant."

Here are the correct spellings and definitions of the words:

• Lapse: A temporary failure or slip in concentration or behavior.
• Recalcitrant: Resisting authority or control; stubbornly disobedient.
• Acquit: To declare someone not guilty of a criminal charge or to fulfill one's responsibilities or duties.
• Mourning: The expression of deep sorrow or grief, especially over someone's death.