OMG! is an acronym for 'Oh My God!' and is used to express shock, surprise, or excitement. It is often used in informal conversations and text messages. The crossword solutions YIPE (4 letters), GASP (4 letters), and YIKES (5 letters) are all words that can be used to express similar sentiments as OMG!. Yipe is an exclamation of surprise or excitement, GASP is an expression of shock or amazement, and yikes is an expression of fear or dismay.