The word "gricer" is not a widely known term, but it refers to a person who is passionate about trains and train spotting. Synonyms for this term include railfan, train enthusiast, train spotter, or train buff. These words describe individuals who have a deep interest in locomotives, railways, and everything related to train travel. Some other synonyms for gricer might include railroad aficionado, train nerd, or locomotive fanatic. Regardless of the exact term used, these people share a common love for trains and often spend hours watching them, photographing them, or even collecting train memorabilia.