Lewis & Short

anxĭtūdo, ĭnis, f. (mostly ante-class.), and anxĭĕtūdo, ĭnis, f. (post-class. for the class. anxietas) [id.], anxiety, trouble, anguish: animi, Pac. ap. Non. p. 72, 33; Att. ib. 28; 29.
Once also in Cic.: anxitudo prona ad luctum, Rep. 2, 41: macerabatur anxietudine, Aug. Conf, 9, 3: anxietudinis poena, Paul. Nol. Ep. 14.