Panzer on its own translates to (an) "armoured" (thing).
I love the Chelsea tractor -> "Hausfrauenpanzer" allusion. The German might be translated as "The wife's tank" or "The missus' tank" or "Me bird's tank".
The English word tank is the outlier. It's a code word for the initial concept that has stuck and unfortunately ended up as the canonical name for the thing. The word tank in English really used to mean a vessel eg a water tank.
I lived in West Germany in the 1970s/80s ...