The term 'LIKE THE HATTER OF WONDERLAND' can be summarized by the crossword solution MAD, which is an acronym for 'Mentally Affected Disorder'. This is a term used to describe someone who is suffering from a mental illness or disorder. The reference to the Hatter of Wonderland is a reference to the character in Lewis Carroll's novel Alice's Adventures in Wonderland, who is known for his erratic behavior and strange mannerisms.