Green’s Dictionary of Slang

tross n.

also tros
[backsl.]

a sort.

[UK]J. Diprose London Life 43: I’ve had a regular ‘tros-dab’ (bad sort) to day.
[Aus]Sydney Sl. Dict. (2 edn) 11: Dab tros - Bad sort.
[UK]Farmer & Henley Sl. and Its Analogues.

In exclamations