UK usage-

A very big person, normally male who is as broad as he is tall yet carries very little fat. Not the sort of person you would willingly upset.

Term comes from the large brick built outside toilets once common in working class areas of the UK.

When you eat dirt for the first time and leave your family to build a shack in the woods

usually describing a person who is very muscled and tough; impervious, unassailable

Heavy set; stocky; well built. As in “He was built like a brick shithouse”.

Brick shit-house,brick shithouse are also acceptable forms of spelling.

1) a stand alone sturdy toilet constructed from brick.
2) Simile - a large and/or muscular person

A huge motherfucker with gigantic muscles that could fuck up anyone that doesn't take steroids and go to the gym 6 days a week.

originally from an outdoor toilet, now used to describe a big-framed male or female (usually derogatory for the latter)