estrangement

noun

1. The act of estranging or the condition of being estranged: alienation, disaffection. See love/hatred.
2. An interruption in friendly relations: alienation, breach, break, disaffection, fissure, rent², rift, rupture, schism, split. See assemble/disassemble, help/harm/harmless.

estrangement, see defamiliarization.

The noun has 2 meanings:

Meaning #1: separation resulting from hostility
  Synonym: alienation

Meaning #2: the feeling of being alienated from other people
  Synonyms: alienation, disaffection