Green’s Dictionary of Slang

keenness, enthusiasm, energy.

1922		S. Lewis Babbitt (1974) 130: Zenith the Zip City – Zeal, Zest and Zowie.
1927		(con. WW1) P. MacDonald Patrol 74: ‘We goes with a bleedin’ zip an’ zowie ’n everything, I can tell you’.
1946		R.L. Bellem ‘Latin Blood’ in Speed Detective Aug. 🌐 One of those honey blondes with zowie.