Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† arsis, is, f., = ἄρσις, in metre, the elevation of the voice; opp. thesis, depression (in pure Lat., sublatio, Diom. p. 471 P.), Mart. Cap. 9, p. 328; Don. p. 1738 P.; cf. Ter. Maur. p. 2412 P., and Mar. Vict. p. 2482 P.