Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ăgīna, ae, f. [ago], the opening in the upper part of a balance, in which the tongue moves (agitur), Paul. ex Fest. p. 10 Müll.; cf. also Tert. adv. Herm. 41; Pudic. 9.
Hence, ‡ ăgīnātōres dicuntur, qui parvo lucro moventur, Paul. ex Fest. p. 10 Müll.