an essay of an introductory nature, preliminary to a more profound work.
Origin: 1595–1605; < L prōlūsiōn- (s. of prōlūsiō) preliminary exercise, prelude, equiv. to prōlūs(us), ptp. of prōlūdere (prō-pro-1+ lūdere to play; cf. prelude) + -iōn--ion
An essay written as a preface to a more detailed work.
[Latin prōlūsiō, prōlūsiōn-, from prōlūsus, past participle of prōlūdere, to practice beforehand : prō-, before; see pro-1 + lūdere, to play; see leid- in Indo-European roots.] pro·lu'so·ry (-sə-rē, -zə-) adj.