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 gasum could not be parsed. Trying a normal dictionary lookup:
No entries found. Showing closest matches:
gassinades, is, m. (lapis), a Median precious stone, Plin. 37, 10, 59, § 163.
† gaster, tĕris, and tri, f., = γαστήρ, the belly (pure Lat. venter).