1922Emily Post, Etiquette, Chapter 10: Cards and Visits
When a servant at a door says “Not at home,” this phrase means that the lady of the house is “Not at home to visitors.” This answer neither signifies nor implies—nor is it intended to—that Mrs. Jones is out of the house.
Westrobothnian: Lua error in Module:parameters at line 360: Parameter 1 should be a valid language or etymology language code; the value "gmq-bot" is not valid. See WT:LOL and WT:LOL/E., Lua error in Module:parameters at line 360: Parameter 1 should be a valid language or etymology language code; the value "gmq-bot" is not valid. See WT:LOL and WT:LOL/E., Lua error in Module:parameters at line 360: Parameter 1 should be a valid language or etymology language code; the value "gmq-bot" is not valid. See WT:LOL and WT:LOL/E., Lua error in Module:parameters at line 360: Parameter 1 should be a valid language or etymology language code; the value "gmq-bot" is not valid. See WT:LOL and WT:LOL/E.
Westrobothnian: Lua error in Module:parameters at line 360: Parameter 1 should be a valid language or etymology language code; the value "gmq-bot" is not valid. See WT:LOL and WT:LOL/E.
(historical) A type of reception or party whereby the host says they will be ‘at home’ during specific hours, when guests can come and go as they like.
1924, Ford Madox Ford, Some Do Not..., Penguin 2012 (Parade's End), p. 4:
And, as near as possible to the dear ladies who gave the At Homes, Macmaster could keep up the talk – a little magisterially.
1985, Peter Carey, Illywhacker, Faber and Faber 2003, p. 104:
She had gone, with high hemlines, to ‘At Homes’ and balls, and left me jealous, half mad, to cluck with her parents who were concerned she might be mixing with a fast crowd.