The term "smoking carriage" originally referred to a specific compartment on a train designated for smokers. However, with the decline in smoking, this terminology is no longer in widespread use. Some possible synonyms include "smoking section," "smoking area," or "smoking room." Alternatively, one could use phrases like "designated smoking space" or "smoking enclosure." It's important to consider context and audience when selecting synonyms, as some terms may carry negative connotations for non-smokers or those with respiratory issues. Regardless of the terminology used, it's important to respect others' right to clean air and avoid smoking in areas where it is prohibited.