The term 'I CAN'T BELIEVE IT!' can be expressed in a variety of ways, as demonstrated by the crossword solutions SHEESH (6 letters), MAN (3 letters), WOW (3 letters), OHNO (4 letters), and YOURENOTSERIOUS (15 letters). SHEESH is an expression of surprise or disbelief, while MAN is an exclamation of surprise or admiration. WOW is an expression of amazement or awe, and OHNO is an expression of dismay or disappointment. Finally, YOURENOTSERIOUS is an expression of disbelief or incredulity. All of these expressions are used to express the sentiment of 'I CAN'T BELIEVE IT!'