The term 'toward the center' can be expressed in a variety of ways, as evidenced by the crossword solutions given. The four-letter solution 'INTO' implies movement in the direction of the center, while the six-letter solution 'INWARD' suggests a similar motion but with a greater emphasis on the destination. The four-letter solution 'inly' implies a more internalized approach to the center, while the five-letter solution 'INNER' suggests a focus on the innermost part of the center. The seven-letter solution 'INWARDS' is a variation of 'INWARD' and implies a similar motion, while the five-letter solution 'entad' suggests a movement away from the edges and toward the center. The eight-letter solutions 'INWARDLY' and 'MEDIALLY' both suggest a focus on the innermost part of the center, with the former emphasizing the direction of movement and the latter emphasizing the location.