1. someone/something pleasantly different or new and exciting, a short break from something taken outdoors
he/she is a breath of fresh air, step outside for a breath of fresh air
A 'breath of fresh air' can refer to a short time you spend outdoors in order to feel refreshed or revived. Something that is described as 'a breath of fresh air' is something that is new, novel or invigorating. This could be a person with fresh, new ideas and approaches, or something inspiring and new.