(Anglo-Saxon, gan, ic ga, I go.)
Here's a go
or Here's a pretty go.
Here's a mess or awkward state of
affairs. It is no go.
It is not workable. “Ça ira,
the French Revolution (it will go), is a similar phrase. (See
Great Go, and Little Go.)
(The). All the go. Quite the fashion; very
popular; la vogue.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894