This, I honestly believe (as Mr Borrow indicates), came from _Rum_ or _Rom_, a Gipsy.

It is a peculiar word, and all of its peculiarities might well be assumed by the sporting Gipsy, who is always, in his way, a character, gifted with an indescribable self-confidence, as are all "horsey" men characters, "sports" and boxers, which enables them to keep to perfection the German eleventh commandment, "Thou shall not let thyself be _bluffed_!"-- _i.e_., abashed.
PAL is a common cant word for brother or friend, and it is purely Gipsy, having come directly from that language, without the slightest change.

On the Continent it is _prala_, or _pral_.

In England it sometimes takes the form "_pel_." TRASH is derived by Mr Wedgwood (Dictionary of English Etymology, 1872) from the old word _trousse_, signifying the clipping of trees.

But in old Gipsy or in the German Gipsy of the present day, as in the Turkish Rommany, it means so directly "fear, mental weakness and worthlessness," that it may possibly have had a Rommany origin.