Phi (ผี)
Phi (ผี) is the Thai term for ghosts and spirits, encompassing everything from the malevolent phi tai hong, ghosts of violent death, to household and nature guardians. Scholarly study began with Phraya Anuman Rajadhon's 1954 essay 'The Phi,' which shows that belief in phi shapes Thai respect for ancestors, ritual offerings, and conduct toward the dead.