Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Pĕta, ae, f. [peto], the goddess of praying or entreaty, Arn. 4, 131.‡ † pĕtălum, i, n., = πέταλον, a metal plate: petalum, aurea lamina in fronte pontificis, quae nomen Dei tetragrammaton Hebraicis litteris habebat scriptum, Isid. Orig. 29, 21.