1 an explanatory statement or account.
2 an explanation or commentary.
3 Mus. the part of a movement, esp. in sonata form, in which the principal themes are first presented.
4 a large public exhibition.
5 archaic exposure.
Derivatives:
expositional adj. expositive adj.
Etymology: ME f. OF exposition, or L expositio (as EXPONENT)
Useful english dictionary. 2012.