Yomp is Royal Marines slang describing a long distance march carrying full kit.

The most famous yomp of recent times was during the 1982 Falklands War. After disembarking from ships at San Carlos on the East Falkland, on May 21st 1982, Royal Marines and members of the Parachute Regiment yomped (and tabbed) with their equipment across the islands, covering eighty miles in three days carrying enormous loads.

Media coverage of this war saw the term Yomp become well known and was in general use. However the term has since faded somewhat from general use in the decades since the end of the Falklands war.

British Army slang for the same thing is tab.