The term 'OIL TO APPLY' can be summarized as the crossword solution 'ANOINT, ' which is a 6-letter word. Anointing is a religious ritual in which oil is applied to a person's head or body as a sign of blessing, consecration, or initiation. It is a practice that has been used in many religions, including Christianity, Judaism, and Islam. In Christianity, anointing is often used in baptism ceremonies and during healing services. In Judaism, it is used in the coronation of kings and in the consecration of the high priest. In Islam, it is used in the ritual of wudu, which is the washing of the hands, face, and feet before prayer.