Wiktionary
a. (context idiomatic English) Finishing in last place in a competition or (in sports) the standings, often by a considerable margin to the next-to-last-place finisher or after an exceptionally poor showing or season.
Wikipedia
Dead Last is an American drama- comedy- fantasy television series, produced by Warner Bros. in 2001. It starred Tyler Labine as Scotty Sallback, Kett Turton as Vaughn Parrish, and Sara Downing as Jane Cahill. The series ran for one season with 13 episodes produced but only 8 of them aired. All 13 episodes were aired on YTV and all 13 episodes were often shown on the Trouble channel in the UK until the parent Virgin network closed it.
Usage examples of "dead last".
The dead last thing she wanted was any of the other detectives noticing, especially her new and keenly perceptive partner.
They'll interview his friends, and his friends will tell them he was at Club Dead last night, and they'll check it out.
Bessany Weyman's research station sits dead last on Sector Command's list of priority defense sites.
Long enough for him to see all three captives trying to gain their feet, and Mouse dead last in the race.