The story
By surface analysis, improvisation + -al, or, by surface analysis, improvise + -ation + -al.
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: Having the nature of an improvisation. Full definition →
By surface analysis, improvisation + -al, or, by surface analysis, improvise + -ation + -al.
Etymology from Wiktionary, CC BY-SA 4.0.