The term 'Little Stream' can be described by two crossword solutions: RILL (4 letters) and RUNLET (6 letters). A RILL is a small stream or brook, usually shallow and narrow. It is typically formed by the erosive action of flowing water in a channel on the Earth's surface. A runlet is a small stream or brook, usually shallow and narrow. It is typically formed by the erosive action of flowing water in a channel on the Earth's surface, but it is smaller than a RILL.