overfast adjective 1adverb 1verb 1forms 5 adjective1 •Too quick. adverb1 •Too quickly.MacDonald shook his head. “Man, you are surely travelling overfast,” said he. “I have heard no evidence yet that any stranger was ever in the house at all.” — 1914 verb1 •To refrain from food to an excessive degree.[…] overfasting could make a monk too exhausted to pray […] — 2023 formsoverfasted · overfasting · overfasts · more overfast · most overfast