Double-end is a term that is commonly used in various contexts, referring to the presence of two ends. Some synonyms that can be used instead of double-end include "dual-ended," which means something that has two ends, "bi-terminal," which means something that has two terminals or connection points, "ambidextrous," which means someone or something that can use either hand equally well, and "amphidromous," which means something that moves between salt and freshwater environments. Other potential synonyms for double-end include "bilateral," "two-sided," "duplicitous," "two-faced," "deceitful," and "duplicative." The use of these synonyms can help add variety to your writing, instead of relying on the same phrases repeatedly.