Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
angusto, āvi, ātum, 1, v. a. [angustus], to make narrow, to straiten (first used after the Aug. per.): Cujus (Hellesponti) iter caesis angustans corporum acervis, Cat. 64, 359: (puteus) ore angustatur, Plin. 17, 8, 4, § 45: servorum turba, quae quamvis magnam domum angustet, Sen. Cons. ad Helv. 11: maris angustat fauces, Luc. 5, 232: angustare aëris meatus. id. 4, 327: animam in artus tumidos angustare, Stat. Th. 4, 827; 12, 665.
Trop., to circumscribe, restrain: gaudia sua, Sen. Cons. ad Polyb. 29: angustanda sunt patrimonia, id. Tranq. 8.