Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
trŭa, ae, f. 
- I.  A stirring-spoon, skimmer, ladle, Titin. and Pompon. ap. Non. 19, 17 sq.; cf. Varr. L. L. 5, § 118 Müll.
- II.  Perh. a drain, gutter, spout, acc. to Varr. l. l.