Is it farther or further?
1903, from xeno- "foreign, strange" + -phobia "fear." Earlier (c.1884) it meant "agoraphobia."
xenophobia xen·o·pho·bi·a (zěn'ə-fō'bē-ə, zē'nə-)n. Fear and contempt of strangers or foreign peoples.
An unreasonable fear, distrust, or hatred of strangers, foreigners, or anything perceived as foreign or different.