The term 'breath of air' can be broken down into four crossword solutions: WIND (4 letters), GASP (4 letters), SMOG (4 letters), and SIGH (4 letters). WIND is a natural phenomenon caused by the uneven heating of the atmosphere, which results in air currents. GASP is an expression of surprise or shock, usually accompanied by a sudden intake of breath. SMOG is a type of air pollution caused by the burning of fossil fuels, which can cause respiratory problems. Lastly, a SIGH is an expression of relief or disappointment, usually accompanied by a long exhale of breath.