The phrase "within the termini" often refers to something that is limited or contained within a specific area or boundary. Some synonyms for this phrase include "within the bounds," "within the limits," "within the confines," "within the parameters," and "within the perimeters." These words all convey the idea of something being restricted to a certain space or range. Whether you're describing a legal agreement, a physical location, or a personal goal, using one of these synonyms can help you communicate the concept of being restricted or constrained within a specific set of parameters.