Final answer:
The second syntactic indicator for identifying a noun is its syntactic role in a sentence, which refers to how the word is used within the structure of the sentence.
Step-by-step explanation:
The second syntactic indicator to determine whether a word is a noun or not is its syntactic role in a sentence. This means examining how the word functions within the sentence's structure. For instance, nouns can often be identified by their role as subjects, direct objects, indirect objects, or objects of prepositions. The other options like taste, etymology, or position in the alphabet do not serve as indicators for determining the syntactic category of a word.