{v. phr.} To be forced to; can only; must. * /When the streets are full of melting snow, you can't help but get your shoes wet./ * /When a friend gave Jim a ticket to the game, he couldn't help but go./ * /When a close friend dies, you cannot but feel sad./ Compare: CAN HELP, HAVE TO.
CANNOT BUT
Meaning of CANNOT BUT in English
Dictionary of English idioms . Словарь английских идиом. 2012