Lewis Short
(adjective) : infīnītīvus, a, um, id.
* Unlimited, indefinite: modus, or absol.: infī-nītīvus, i, m.; in gram.,the infinitive,Mart. Cap. 3, § 310 sqq.; Isid. Orig. 1, 8; Diom. p. 331 P. al.
Charlton T. Lewis, Charles Short, A Latin Dictionary