Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
expensa, ae, f. (sc. pecunia) [expendo], a disbursement, expense (post-class.): neque tempus neque finem expensarum habet, Dig. 27, 10, 1: non indecores aeraria lassant expensae, Claud. II. Cons. Stil. 145.