What's the meaning of the phrase 'All agog'?
To be all agog is to be excited, in high spirits; in eager expectation.
What's the origin of the phrase 'All agog'?
Agog is a strange word in that it doesn't really exist by itself; it is only ever used as part of 'all agog' or, very occasionally, 'set agog'. When did you last hear of anyone being a little bit agog?
The derivation is probably from the French 'en gogues', meaning 'in mirth'. If that is the source, it crossed the English Channel very early. The first reference to 'agog' in English is Nicolas Udall's Apophthegmes of Erasmus, 1542:
"Beeying set agog to thinke all the worlde otemele." [oatmeal]
The first sighting of 'all agog' is in William Cowper's The Diverting History of John Gilpin, 1782:
So three doors off [away] the chaise was stayed,
Where they did all get in;
Six precious souls, and all agog
To dash through thick and thin.