means the quality of being perceived as fundamentally different from oneself or one's group, often in a way that sets someone apart as alien or outsider.

from A straightforward English build: "other" plus the noun-making suffix "-ness," which has been turning adjectives into abstract nouns since Old English (compare "goodness," "darkness"). "Other" itself is ancient, from Old English "oþer," with cousins across the Germanic languages and roots reaching back to Proto-Indo-European. The plain word is old, but "otherness" as a weighty term — the condition of being the Other — was sharpened by 20th-century philosophy and social theory, where thinkers used it to name how groups define themselves by deciding who doesn't belong.