What is "tommy cooker"

n. (context slang military archaic English) the M4 Sherman tank, due to its likelihood to "brew up" and explode after being hit by German tank fire in WWII.

A Tommy cooker was a compact, portable stove, fuelled by something referred to as solidified alcohol which was issued to British troops ( Tommies) in World War I. It was notoriously ineffective; one soldier complained that it took two hours to boil half a pint of water. A variety of commercial or improvised alternatives were in use.

A refined version remained in use during World War II, using gelled fuel in a tin can; a steel ring fitted to the can supported a mess tin.

The British army still uses compact portable solid fuel ( hexamine) stoves.

The term also came to be applied by the German tank crews as a derogatory nickname for the Sherman tank whose earlier models acquired a reputation for bursting up in flames when hit, due to improper ammunition storage.