Green’s Dictionary of Slang

t.t.f.n. phr.

[ta-ta for now, orig. created and popularized on comedian Tommy Handley’s BBC Radio show ITMA (It’s That Man Again, 1939–49). Dorothy Summers, as ‘Mrs Mopp’ (the comic charlady) actually used the phr., which was revived by BBC Radio 2 disc jockey Jimmy Young (b.1923)]

[1940s+] goodbye.