The term 'MAIN Burden' can be broken down into two words, 'MAIN' and 'Burden'. The word 'MAIN' is an adjective meaning 'PRINCIPAL' or 'CHIEF', while the word 'Burden' is a noun meaning 'a heavy load of responsibility'. Together, the phrase 'MAIN Burden' refers to the primary responsibility or duty of a person or group. The crossword solution for this term is 'BRUNT', which is a verb meaning 'to bear the BRUNT of something'. Therefore, the phrase 'MAIN Burden' can be interpreted as bearing the MAIN responsibility or duty of a task.