TASH is an Irish word for a ghost that can appear in human or animal form. Ireland has a strong ghost story tradition and gave birth to one of the greatest ghost-story writers of the nineteenth century, Sheridan Le Fanu (1814–73). Irish folklore is particularly rich in legends about phantom horses, birds, rabbits and even insects such as butterflies.

A large number of these ghosts are believed to be the spirits of people who have died a violent death, either having been murdered or having committed suicide, and condemned to haunt the place where they died as a lesson for others. In many parts of Ireland it is considered unwise among the superstitious to mourn a person for too long, ‘or else they will be kept from their rest and return as a ghost’.

SOURCE:

The Element Encyclopedia of Ghosts and Hauntings: The Complete A–Z for the Entire Magical World: The Ultimate A-Z of Spirits, Mysteries and the Paranormal by Theresa Cheung