porrectio

porrectĭo, ōnis, f. [1. porrigo],

I a stretching out , extending , extension : digitorum (opp. contractio), Cic. N. D. 2, 60, 150: bracchii, Auct. Her. 3, 15, 27.—

II Concr., a straight line (opp. circinatio), Vitr. 10, 3, 8.