The connecting peptide, also known as C-peptide, is a hormone precursor produced in the pancreas alongside insulin. However, when exploring antonyms for the term, one could consider words that denote disconnection, dissociation, or non-relation. For example, "disintegrating peptide," "removing peptide," or "uncoupling peptide." These terms challenge the idea of a peptide that connects or binds together, suggesting instead that the peptide has the opposite effect of breaking apart or separating. While these antonyms may not be technically accurate in terms of the function of C-peptide, they offer a creative and linguistically interesting way to play with the idea of opposites.