The term "cropt up" is commonly used to describe situations where something unexpectedly appears or arises. Its antonyms include phrases that denote the absence or non-existence of something. For instance, "disappeared", "vanished", and "vanished into thin air" are antonyms for the phrase "cropt up." Other antonyms include "dwindled", "declined", and "diminished", which imply a decrease in something. Similarly, "abolished", "extinguished", and "erased" suggest the complete removal or termination of something. Overall, the antonyms for "cropt up" convey a sense of absence, decrease or complete disappearance, indicating the opposite meaning to the original phrase.