The term 'DEEP ANGER' can be broken down into two crossword solutions: IRE (3 letters) and BILE (4 letters). IRE is a noun that means a feeling of intense anger or annoyance. It is derived from the Old English word iren, which means wrath. BILE is a noun that refers to a bitter, yellow-green secretion produced by the liver and stored in the gallbladder. It is released into the small intestine to aid in digestion. Together, these two words describe a deep and intense anger that is difficult to control.