What does albicilla mean in Latin?

albicilla, a noun, means “a white-tailed eagle, Haliaeetus albicilla”.

What is the genitive of albicilla?

The genitive singular is albicillae. albicilla is feminine, first declension.

noun · femininefirst declension

albicilla f (genitive albicillae)

femininea white-tailed eagle, Haliaeetus albicilla
Pygargus, Albicilla Gazæ, quibusdam Hinnularia. Pygargus, for Gaza [called] albicilla, for certain people Hinnularia.1713, John Ray, Synopsis methodica avium & piscium page 7, number 5
Pygargus (one says because of its whitening tail, just as if you'd call it albicilla, as Gaza adds on his own accord1551 – 1558, Conrad Gessner, Historia animalium page 199, lines 30-31:. Pygargus (ab albicante cauda dicitur, ac si albicillam nomines, ut Gaza de suo addit)

From albus (“white”) + New Latin cilla (“tail”).