1911 Encyclopædia Britannica/Fossick

FOSSICK (probably an English dialectical expression, meaning fussy or troublesome), a term applied by the gold diggers of Australia to the search for gold by solitary individuals, in untried localities or in abandoned diggings. A “fossicker,” or pocket miner, is one who buys up the right to search old claims, in the hope of finding gold overlooked by previous diggers.