jark noun 1verb 1forms 3 noun1 •A seal (stamp or impression of a stamp)."This is a jark from Jim Ratcliffe," said the taller, having looked at the bit of paper. — 1818 verb1 •(UK, slang) To modify (weaponry) to disadvantage; especially, to attach a tracking device to and covertly monitor the location of (a weapon).At the end of the day, it was inevitable that the IRA would discover that its weapons were being jarked. — 1996 formsjarked · jarking · jarks