The term 'call in' can refer to a variety of activities. The three letter solution, 'LET, ' implies allowing something to happen or giving permission. The six letter solution, 'RECALL, ' suggests bringing back something that was previously known or remembered. The seven letter solutions, 'CONVENE' and 'CONSULT, ' both suggest gathering people together for a purpose. The four letter solution, 'MEET, ' implies coming together for a discussion or purpose. Finally, the four letter solution, 'NEXT, ' implies continuing on with something. In summary, the term 'call in' can refer to a variety of activities, such as allowing something to happen, bringing back something that was previously known, gathering people together for a purpose, coming together for a discussion, and continuing on with something.