or Gowk. In the Teutonic the word gauch means
fool; whence the Anglo-Saxon geac, a cuckoo, and the Scotch goke or gouk.
Hunting the gowk
[fool], is making one an April fool. (See April.) A gowk
storm is a term applied to a storm consisting of several days of
tempestuous weather, believed by the peasantry to take place
periodically about the beginning of April, at the time that the gowk or
cuckoo visits this country.
“That being done, he hoped that this was but a gowk-storm.” —Sir G. Mackenzie: Memoirs, p.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894