Noun
The quality or state of being nasal.
Source: Webster's dictionaryAlthough some vowels are strongly nasal, instances of distinctive nasality are rare. Source: Internet
It differed from other dialects in vocabulary and pronunciation; it appears to have been spoken with a slight degree of nasality. Source: Internet
This however can be explained in a different way, that the inscription simply fails to note the nasality of the final vowels (like in the established custom of writing cos. Source: Internet