The term itself already implies a positive aspect – it refers to a collection of words, specifically nouns, which is generally considered a valuable resource.
However, if you are looking for a more positive and descriptive phrase, here are some options:
* Comprehensive Noun Dictionaries
* Extensive Noun Dictionaries
* Authoritative Noun Dictionaries
* Valuable Noun Dictionaries
* Essential Noun Dictionaries
The choice of phrase will depend on the context and what aspect you want to highlight.