Went off the deep end is an expression used to describe a person who has become overly emotional or irrational. The crossword solutions for this term are DOVE (4 letters), DIVED (5 letters), and RAGED (5 letters). DOVE is a verb meaning to plunge headlong into water, DIVED is a past tense of the verb dive, and RAGED is a verb meaning to act in a wild, uncontrolled manner. Taken together, these words suggest that someone has become so overwhelmed with emotion that they have acted impulsively and irrationally.