a distinctive and separate event that is part of a larger series, e.g. in history or in somebody's life
a developed situation or incident that is integral to but separable from a continuous narrative, e.g. a play or novel
an instalment of a serialized literary work, radio or television programme, etc
a digressive subdivision or passage introducing a new theme in a musical composition
the part of an ancient Greek tragedy between two songs from the chorus
[Greek epeisodion, neuter of epeisodios coming in besides, from epi- + eisodios coming in, from eis into + hodos road, journey]