grinchy /ˈɡɹɪnt͡ʃi/ adjective2 •(informal) Possessing the qualities of a grinch; grouchy; being a killjoy.This grinchy pronouncement by the president had the value of being truthful. — 2025 •Possessing the appearance of the Grinch; green and/or tufty. formsmore grinchy · most grinchy