This definition is slightly confusing, even for a native speaker.
A better clue can be found by looking to the TLFi that says:
Fam. Y aller de qqc. Entreprendre une certaine action :
35. Lacretelle me disait : « Allez-y ! Nommez-vous. Allez-y d'une dédicace... » A. Gide, Journal, 1930, p. 966.
where y aller de is used at the imperative: allez-y de...
The meaning is close to "go for it", "go ahead and do it".
Here are examples matching the definitions given by the Larousse:
- engager une certaine somme :
J'y vais de 5 francs ! → I'm betting 5 Francs on it. (outdated)
- produire quelque chose comme contribution :
Il y va encore de son discours habituel → He brings us again his usual speech.
Note that there is another y aller de expression that is not informal and shouldn't be confused with the one just mentioned, e.g. Il y va de mon honneur. With that second expression, the pronoun il is impersonal. It doesn't represent anything/anyone. Both other replies so far are partially or totally about that other phrase.
See this question for its frequent confusion with en aller de.