Difficulties, generally; a rough time.

A rocket-propelled vehicle constrained to run on a rail, used for experimental purposes.

Alternative spelling of sledhead (a fan) / Alternative spelling of sled head (an injury)

(sports, pathology, slang) A concussion or subconcussive injury caused by tobogganing, including luging, skeleton, bobsledding, tubing; that stereotypically leaves the victim woozy or muddle-headed.

Alternative spelling of sledhead (“a fan of sledding”)

Synonym of sledge hockey

(programming) A series of identical values in memory that instruct the CPU to take no action and proceed to the next instruction, used in shellcode etc. to increase the chances of any random instruction access executing the sequence that follows.

Alternative spelling of threshing sled, synonym of threshing sledge

Synonym of threshing sledge

(idiomatic) Difficult to proceed