manna = "what is it"
1) the food that nourished the Israelites for forty years in the wilderness
2) of the manna was kept in the ark of the covenant
3) symbolically, that which is kept in the heavenly temple for the food of angels and the blessed
Part of Speech: noun neuter
Citing in TDNT: 4:462, 563
Of Hebrew origin [H4478]; manna (that is, man), an edible gum: - manna.
These two sites give similar information, with the definition from several dictionaries and statistics on the use of the word.
Perseus Digital Library
University of Chicago's Logion lexicon
Thayer's dictionary plus other information.
From this site's dictionary (in Italian)
Click on the first column to search for that word as a form of the root μάννα; click on the second column to search for that grammatical form of the root μάννα; click on the third column to search for that word and grammatical form; click on the total to search for the root μάννα.