The phrase "chink the armor" means to find a weakness in someone's defense or argument. Some synonyms for this phrase are "poke a hole," "expose a flaw," "reveal a vulnerability," "uncover a weakness," and "spot a blemish." These phrases all convey the idea of discovering a weakness or a gap that can be used to attack or refute an argument or a position. It is important to use synonyms creatively to strengthen one's speech and to avoid repeating the same words or phrases repeatedly. Having a diverse vocabulary makes communication more effective and meaningful.