I’ve done some fossicking about this word
As fans of Poldark will know, and I’m sure the lingering camera shots of Ross Poldark’s shirtless torso (Aiden Turner) scything the grass had nothing to do with it
nor him coming out of the sea dripping wet, trousers / pants clinging lovingly to his tautly muscled thighs… ,
the main industry in 18th (and 19th) century Cornwall (southwest England) was copper and tin mining (since the Bronze Age) and many Cornish miners emigrated during this period to Australia to make their fortunes there, taking their language with them - including this Cornish dialect word
FOSSICK, v. Cor.3 [fosik.] To obtain by asking, ' ferret out.'
The above is an extract from vol. II of the 6 volume The English Dialect Dictionary, by Joseph Wright (pub from 1898). Joseph Wright was Diebold Professor of Comparative Philology (historical linguistics) at Oxford University and, interestingly, was a tutor of the student JRR Tolkien. Wright had a significant impact on Tolkien’s life and influenced his fascination with language, which is at the heart of LoTR and The Silmarillion.