A true sedative is a substance that helps to calm and relax the mind and body. If you are looking for synonyms for the term "true sedative," you may want to consider terms like tranquilizer, relaxant, hypnotic, anxiolytic, or sleep aid. Each of these terms refers to substances or methods that can help to reduce anxiety and promote sleep, but they may have slightly different mechanisms of action or effects on the body. For example, tranquilizers are often used to reduce anxiety or agitation, while anxiolytics specifically target anxiety, and hypnotics are used to induce sleep. Depending on your needs and preferences, you may find one of these synonyms to be a more appropriate choice than "true sedative".