breathless vs breathtaking

breathless and breathtaking both are adjectives.

Word	Noun	Adjective	Verb	Adverb
breathless	No	Yes	No	No
breathtaking	No	Yes	No	No

As adjectives, breathless and breathtaking are synonyms defined as:

breathless and breathtaking: tending to cause suspension of regular breathing

breathless (adjective)	breathtaking (adjective)
not breathing or able to breathe except with difficulty	tending to cause suspension of regular breathing
appearing dead; not breathing or having no perceptible pulse
tending to cause suspension of regular breathing