The term 'attack vigorously' can be expressed in several ways through crossword solutions. The six-letter word 'ASSAIL' means to attack with strong or aggressive criticism. The four-letter word 'PELT' means to attack with a barrage of missiles or stones. The seven-letter word 'ASSAILS' is the third person singular form of 'ASSAIL'. The five-letter word 'layto' means to attack with vigor. The six-letter word 'wadein' means to attack with determination and courage. The seven-letter word 'layinto' means to attack with great force. Finally, the eight-letter word 'tearinto' means to attack with great ferocity. All of these words describe attacking with great energy and intensity.