What's that when it's at home

Posted by R. Berg on August 13, 2002

In Reply to: What's that when it's at home posted by Kathy on August 13, 2002

: I am interested to learn of the derivation of the phrase "what's that when it's at home", where 'that' can be a word that the speaker/writer does not understand the meaning of.

: with thanks
: Kathy

Eric Partridge, Dictionary of Catch Phrases: American and British, from the Sixteenth Century to the Present Day, has an entry for it but doesn't say where it came from.

From Partridge:
"What is that" (or "what's that") "when it's at home?"; and "who is he" (or "she") "when he's" (or "she's") "at home?" C20 tags, implying either derision or incredulity, and signifying 'I've never even heard of her, him, it'. Edwin Pugh uses it in 'The Cockney at Home', 1914, and Dorothy L. Sayers in 'Have His Carcase', 1932, has: 'Haemophilia. What in the name of blazes is that, when it's at home?' . . . It is, in short, directed esp. at someone employing an unusual or erudite or highly technical or scientific term in a milieu unlikely to know its meaning.