The crossword solutions for the term SPUR, WITH 'ON' are URGE and EGG. The term 'spur on' is an idiom meaning to encourage or motivate someone to do something. It is often used in the context of providing support or encouragement to someone to help them achieve a goal. The two words URGE and EGG are both related to this idiom, as they can be used to describe the act of motivating someone. URGE is a verb that means to strongly encourage or URGE someone to do something, while EGG is a noun that can refer to the encouragement or support given to someone.