don’t-know-what-to-call-’ems, n. — Green’s Dictionary of Slang

don’t-know-what-to-call-’ems n.

also don’t name ’ems, don’t-speak-of-’ems

[euph.; the image of trousers, so close to the genitals and legs, as ‘obscene’ or taboo]

trousers.

1835		G. Kent Modern Flash Dict. 12: Don’t name ’ems – breeches. Don’t know what to call ’ems – inexpressibles, breeches.
1848		Flash Dict. in Sinks of London Laid Open [as cit. 1835].
1849		G.G. Foster N.Y. in Slices 121: Finding our best black coat rather seedy at the elbows, our don’t-know-what-to-call-’ems grievously afflicted with ‘kneeholes,’ and our waistcoat minus several of its most important buttons.
1864		O.W. Norton Army Letters (1903) 216: Who should I see but Mr. Johnny just getting into his don’t-speak-of-’ems [HDAS].
1890–1904		Farmer & Henley Sl. and Its Analogues.