The term 'put in firmly' can be summarized by the crossword solution 'enroot'. This is a verb meaning to establish something firmly, or to fix it in place. It is often used in reference to plants, as when a gardener enroots a plant in the soil. It can also be used figuratively, such as when someone enroots an idea in their mind. In either case, the idea is that something is being established firmly and securely.