Definition of "tortuous"

The badger made his dark and tortuous hole on the side of every hill where the copsewood grew thick.

1848, Thomas Babington Macaulay, The History of England from the Accession of James the Second, volume 1, Porter & Coates, page 243

The Southern acquired them because the little Class "B4" 0-4-0 tanks were finding heavy modern rolling stock more and more of a handful, and at war's end the railway had nothing of suitable power but short wheelbase on its books to take their place on the more tortuous of the dock lines.

1959 February, G. Freeman Allen, “Southampton—Gateway to the Ocean”, in Trains Illustrated, page 91

It still takes almost half a year for the average veteran’s claim for disability benefits to be decided in a tortuous process that can involve four separate hearings.

2007 October 6, “Slogging on the Home Front”, editorial in The New York Times

But the early Tubes still tended to follow the public streets in order to save money, hence some tortuous curves.

2012, Andrew Martin, Underground Overground: A passenger's history of the Tube, Profile Books, page 109

Infortunate ascendent tortuous.

1872, Walter William Skeat, Chaucer's A Treatise on the Astrolabe