So, I can't quite work out how this came up, but yesterday over lunch I discovered that 'boob tube' is an American expression for the TV.
Not in the UK.
I believe the American equivalent would be 'tube top'.
I was going to link to an image of one in case anyone was still uncertain about the garment being referred to, but I couldn't find any pictures that were appropriate for family viewing. You'll have to use your imaginations, or ask a friend.
It reminds me of something I saw recently about a man who, when asked which languages he spoke, replied, 'I speak English and Australian fluently, but I generally understand American too.' So true.
