Lifesaver/ˈlaɪfseɪvər/ Definition 1 of 3Pro Tip 1/3Metaphorical Use Consider 'lifesaver' metaphorically to mean extremely helpful, not literally saving a life. This study guide was a lifesaver for my exams. Pro Tip 2/3Emotional Gratitude Express your deep appreciation when something or someone remarkably eases your difficulties. Thanks for your help – you’re a lifesaver! Pro Tip 3/3Non-crisis Scenarios Use 'lifesaver' even in everyday non-emergency situations where someone lends a hand. Finding a restroom in time was a lifesaver.