TTFN

Etymology
In 1939, initialisms, previously rarely used except by the military, were heard more frequently by the British public. ITMA satirised them by coining TTFN, a "pointless" initialism (no easier to say than the phrase on which it was based) to use as a catchphrase, which became widely repeated in the UK. Thirty years later, American ventriloquist Paul Winchell, following the suggestion of his third wife, Jean Freeman, who was British, improvised it as a signature phrase for the (originally British) character Tigger in the Disney films based on A. A. Milne's book The House at Pooh Corner. This, in a world now accustomed to them, popularised worldwide a word originally coined to make fun of initialisms.

Phrase

 * 1) ; goodbye
 * 2) * 1941-1945: (A catchphrase of Mrs Mopp (Dorothy Summers) in several series of the weekly topical comedy British radio programme It's That Man Again (ITMA))
 * 3) * 1966: Catwoman (played by Julie Newmar) in the Batman episode "Better Luck Next Time" – Catwoman: "'TTFN", Batman: "What does that mean?", Catwoman: "Ta-ta for now."
 * 4) * 1974: Tigger (voiced by Paul Winchell) in Unbouncing Tigger – Well, I gotta go, now! I got a lot of bouncing to do! Hoo-hoo-hoo! TTFN! Ta ta for now!