Securicula, læ, f. ge. penu, corr. Diminutiuum. Plinius. An hatther.
Lewis and Short: Latin dictionary
sĕcūrĭcŭla, ae, f.dim. [securis]. I.A little axe, a hatchet, Plaut. Rud. 4, 4, 114 sq.; Mart. 14, 35in lemm. (but Plin. 18, 19, 49, 177, sericulam).—II.Transf., in carpentry, a mortise in the shape of a hatchethead, a dovetail, Vitr. 4, 7, 4; 10, 17 (10, 11, 8).