Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
hĭrūdo, ĭnis, f. (also called sanguisūga), a leech, blood-sucker, Plin. 32, 10, 42, § 122: ego me convortam in hirudinem atque exsugebo sanguinem, Plaut. Ep. 2, 2, 4.
Fig., of any thing that exhausts, etc.: aerarii, Cic. Att. 1, 16, 11: non missura cutem, nisi plena cruoris, hirudo, Hor. A. P. 476.