The Proto-Indo-European word *ghostis
Word *ghostis
Meaning enemy, stranger, guest
See also Linear B: ke-se-nu-wi-ja ‘foreign’
Phrygian: ΞΕΥΝ- ‘personal name, host, stranger’
Linear B: ke-se-nu-wo ‘foreigner, guest’
Synonyms *des-

Other words that might be of interest
*koro- ‘war’, *k̂at- ‘battle’, *skolmehₐ ‘sword’