Skulked is an intransitive verb meaning to move stealthily or sneak around. It is often used to describe the behavior of animals, such as cats or foxes, but can also be used to describe people who are trying to avoid being seen. The crossword solutions CREPT and SLUNK both have five letters and are synonyms for skulked. CREPT means to move slowly and carefully, while SLUNK means to move in a low, slinking manner.