Trenching on is a phrase that indicates encroachment, infringement, or violation of someone's right or territory. There are several synonyms for this phrase, including trespassing, intruding, transgressing, encroaching, and violating. These words express the same idea of going beyond the limits or boundaries of something or someone else's property, space, or authority. Trespassing is a term often used in legal contexts, while intruding suggests entering without permission. Transgressing implies breaking the rules or laws, while encroaching connotes gradual and insidious invasion. Violating suggests intentional or deliberate infringement. All of these synonyms convey the idea that someone is infringing on another's rights or space, whether intentionally or unintentionally.