When it comes to double-action, there are various synonyms that can be used to express its meaning. Some of these synonyms include binary, dual-purpose, two-fold, twofold, and two-way. All these synonyms represent the idea of something that requires two actions or has two effects. Double-action can also be referred to as bilateral, mutual, or reciprocal, describing an action that involves or affects two parties in a balanced way. Additionally, double-action can be expressed as duplex, implying that there are two identical or similar specimens or parts of something. In summary, understanding the synonyms of double-action can help one express its meaning more effectively in various contexts.