2217: 'piping' hot Jan 9, 2021

The phrase 'piping hot' is pretty common, but the pipes in question might not be immediately evident. This is probably not how the word would be used today, but the phrase is attested since the 14th century from Chaucer:

He sente hir pyment meeth and spiced ale

And wafres pipyng hoot out of the glede.

[He sent her sweetened mead and well-spiced ale

And waffles piping hot out of the fire]

It is generally understood these days that the 'piping' in question is in reference to a sizzling or boiling sound from cooking likened to musical pipes.