PROLUSION
prolusion, tune-up, warm-up
(noun) exercising in preparation for strenuous activity
foreword, preface, prolusion
(noun) a short introductory essay preceding the text of a book
Source: WordNet® 3.1
Etymology
Noun
prolusion (plural prolusions)
A trial before the principal performance; a prelude.
An introductory essay.
Source: Wiktionary
Pro*lu"sion, n. Etym: [L. prolusio, fr. proludere to prelude; pro
before + ludere to play: cf. F. prolusion, It. prolusione.]
Definition: A trial before the principal performance; a prelude; hence, an
introductory essay or exercise. "Domestic prolusions." Thackeray.
Her presence was in some measure a restraint on the worthy divine,
whose prolusion lasted. Sir W. Scott.
Source: Webster’s Unabridged Dictionary 1913 Edition