Which source of knowledge, according to the classical Indian school of logic, is defined as the statement of a trustworthy person (aptavakya) and consists of understanding its meaning?

Knowledge from the statement of a trustworthy person (aptavakya) plus grasp of its meaning is shabda.

In Nyaya, shabda is verbal testimony, a distinct source of valid knowledge (pramana).

It requires a reliable speaker (apta) and the hearer's understanding of the sentence-meaning.

The knowledge arises from words, not from perception or inference.

This trustworthy-testimony source is named shabda pramana.