The term 'disappeared gradually' can be summed up by the crossword solution 'FADED, ' which is a five-letter word. Fading is a gradual process of becoming less visible or disappearing over time. It is often used to describe the gradual loss of color in an object, such as a painting or photograph, or the gradual weakening of a sound or light. Fading can also refer to the gradual disappearance of something from memory or consciousness.