There are several synonyms for the phrase "under prove" that can be used to convey the same meaning. These synonyms include "not enough evidence," "not fully substantiated," "unproven," "unsupported," and "unconfirmed." These words are often used in legal or scientific contexts to describe situations where a claim or hypothesis has not yet been fully proven or supported by evidence. While these words may have slightly different connotations or nuances in meaning, they all effectively communicate the same idea of a lack of conclusive evidence to support a claim or assertion.