Lewis Short
(adjective) : pĕr-angustus, a, um
* Very narrow (good prose): fretum,Cic. Verr. 2, 5, 66, § 169: aditus,Caes. B. G. 7, 15; Curt. 3, 4, 4: via,Liv. 22, 4: semita,Curt. 7, 11, 1: termini Macedoniae,Just. 7, 1, 2.—Adv.: pĕrangustē, very narrowly, Cic. de Or. 1, 35, 163.
Charlton T. Lewis, Charles Short, A Latin Dictionary