n (figuratively) That which causes stress or is extremely difficult, especially that which may cause failure at a task.
n (figuratively) Something that is so far ahead of its competition that it effectively kills off that competition.
n (sports) A knockout form of darts involving several players.
n A diacritic mark used in Indic scripts to suppress an inherent vowel (e.g., the Hindi viram, the Bengali or Oriya hasanta) or render the entire syllable silent (e.g., the Burmese virama, the Khmer toandakhiat).