A shirt often worn when one is drinking tea, this definition dates back from early english explorers in africa in the late 1600's when these would be referred to as Tea-shirts. Later in the industral revolution, snotty urchins could not spell 'tea' so the word was shortened to Tea
I'll put the kettle on while you change into you T-shirt
Typical protective fabric covering of the fashionably lazy, so named for the T-shape it has when laid flat. T-shirts may be short- or long-sleeved and often feature witty phrases emblazoned in a variety of interesting and hard-to-read fonts.
He wore a T-Shirt and jeans, neither the worse for being stored carefully on his bedroom floor.