Lewis & Short

occāsĭuncŭla, ae, f. dim. [occasio], an occasion, opportunity (ante- and post-class.): nimis argute me obrepsisti in eāpse occasiunculā, Plaut. Trin. 4, 2, 132; Schol. Bob. ad Cic. Planc. 34; Hier. in Isa. 7, 21, v. 3.