Wordnet 3.0
NOUN (1)
1.
a medieval book (usually illustrated) with allegorical and amusing descriptions of real and fabled animals;
The Collaborative International Dictionary of English v.0.48:
Bestiary \Bes"ti*a*ry\, n. [LL. bestiarium, fr. L. bestiarius
pert. to beasts, fr. bestia beast: cf. F. bestiaire.]
A treatise on beasts; esp., one of the moralizing or
allegorical beast tales written in the Middle Ages.
[1913 Webster]
A bestiary . . . in itself one of the numerous
medi[ae]val renderings of the fantastic mystical
Zoology. --Saintsbury.
[Webster 1913 Suppl.]
WordNet (r) 3.0 (2006):
bestiary
n 1: a medieval book (usually illustrated) with allegorical and
amusing descriptions of real and fabled animals