adjective not breathing or able to breathe except with difficulty
dyspnoeal; dyspneic; dyspneal; dyspnoeic.
breathless at thought of what I had done
breathless from running
followed the match with breathless interest
adjective satellite tending to cause suspension of regular breathing
breathtaking.
a breathless flight
breathtaking adventure
adjective satellite appearing dead; not breathing or having no perceptible pulse
pulseless; inanimate.
an inanimate body
pulseless and dead
WordNet
Breath"less adjective
Definitions
Spent with labor or violent action; out of breath.
Not breathing; holding the breath, on account of fear, expectation, or intense interest; attended with a holding of the breath; as, breathless attention.
But breathless, as we grow when feeling most.
Byron.