Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
The word crataegus could not be parsed. Trying a normal dictionary lookup:
No entries found. Showing closest matches:
† crătaegum, i, n., = κραταιγόν, the kernel of the fruit of the box-tree, Plin. 16, 30, 52, § 120.