There are many synonyms for the word "painlessly" which can be used in different contexts. Some of the synonyms of this word are effortlessly, smoothly, easily, comfortably, and tenderly. These words can be used to express the idea of performing a task or undergoing a procedure without any discomfort or pain. For example, a dentist may use an anesthetic to help a patient undergo a procedure effortlessly. Similarly, a lubricant may be used to make a machine run smoothly. Overall, these synonyms of "painlessly" can be used to convey the idea of comfort, ease, and efficiency in whatever task or situation one is facing.