Green’s Dictionary of Slang

jonah’s whale n.

[rhy. sl.]

a tail.

[UK]G.R. Sims ‘Tottie’ Dagonet Ditties 127: Then a bow-wow by her side, / Who till then had stood and tried / A ‘Jenny Lee’ to banish, / Which was on his ‘Jonah’s whale,’ / Gave a hydrophobic bark.