1
general::
Extremely uncertain or risky, as in It was touch and go after the surgery; we were not sure he'd survive it, or It was touch and go but they finally gave me a seat on the plane. This idiom implies that a mere touch may cause a calamity. [Early 1800s]
American Heritage Idioms
2
general::
Phrase(s): touch-and-go
very uncertain or critical. • Things were touch-and-go at the office until a new manager was hired. • Jane had a serious operation, and everything was touc-hand-go for two days after her surgery.
McGrawhill's American Idioms And Phrasal Verbs