English
improvisatory
By surface analysis, improvise + -atory.
Equivalent to improvise + -atory
Proto-Indo-European *weyd- ‘to see’
…
Latin vīsus ‘having been seen’
Latin prōvīsus ‘foreseen’
Latin improvisus ‘unforeseen, unexpected’
French improviser ‘to improvise’
English improvise
Today it means
adj Of, pertaining to, or in the nature of improvisation.
Language periods are conventional ranges, not dates for this word.
Etymograph / improvisatory