The term 'CAN'T HELP BUT' is an idiom that expresses inevitability or compulsion. It is often used to express a feeling of being unable to resist something. The crossword solutions for this term are MUST (4 letters), HASTO (5 letters), HAVETO (6 letters), NEEDTO (6 letters), and NEEDSTO (7 letters). All of these words express the idea of having to do something, either out of necessity or obligation.