Feck, probably for its phonetic similarity to another word, has been dropped from the language. That or the lexicographers have become feckless, which means that they lacked the drive or initiative toinclude feck in the dictionary. Feckless means lazy and irresponsible. So, don’t get feckless and dropthe –less, lest somebody totally misinterprets you. In which case, you’ll have to do a fair amount of propitiating.