The term 'OF THOUSANDS' can be broken down into three separate crossword solutions: CAST (4 letters), TENS (4 letters), and ACAST (5 letters). CAST is a verb meaning to throw or fling, usually referring to the action of throwing something with force. TENS is a noun meaning a group or set of ten items. ACAST is a verb meaning to CAST away or discard. Together, these three words can be interpreted as throwing away or discarding groups of ten items, which is a common way of expressing large numbers in the thousands.