Progressing smoothly is a phrase that can be used to describe a situation in which something is going well and without any major issues. In this case, the crossword solutions for the term 'progress smoothly' are SAIL and FLOW. SAIL is a verb that means to travel on water using a boat or ship, while FLOW is a verb that means to move in a continuous stream. Both words can be used to describe the idea of progress that is happening without any major issues or disruptions.