Thank you for your interest.
A funny thing happened to me on the way to finding definitions for "sustain". I noticed that all the definitions consisted of verbs or what I later learned are called "verb phrases" (i.e, "be supportive of," "hold up," "manage to withstand something and continue in spite of it"). Below is an alphabetical list of the various definitions for "sustain" that I was able to obtain by examining several online dictionaries (I hope you like long lists):
admit as valid
affirm...