the post from From: GUEST,max monza on 04 Oct 08 - 04:53 PM gives a good summary of what the songs lyrics would mean, especially if you look at the origin and period when this song came from.
The song "The Stoutest Man in the Forty Twa" is about a Jock McGraw, who was in fact Lance-Sergeant Samuel McGaw of The Black Watch who was in battle with this Highland Regiment over on the Gold Coast of Africa against The Ashantees in 1873.
He in fact received the Victoria Cross (highest medal for a soldier) for his for his gallantry at Amoafu, giving rise to more verse ...

The Ashantees, when they saw the shanks of Jock McGaw,
They turned aboot an' ran awa'.
The rain may rain, an' the snaw may snaw,
The wind may blaw, an' the cock may craw,
But ve canna frichten Jock McGaw,
He's the stoutest man in the Forty Twa.

General info to tie in with these lyrics...
A Scottish soldier is also known as A Jock
The Forty Twa is The Black Watch (RHR) or in English: They were originally formed back in the 18th Century as the Forty Second Regiment.
In the 1800`s (when this story took place) The Black Watch used to recruit from Perthshire in Scotland.

There are now various versions (lyrics) to the same song.