Flat

Flat maybe isn't the right word for this. Flat inspires visions of trundling along the road with a bit of a wobble; going into a garage and putting some air into it.
This particular tyre quietly went pop while reversing down a kerb, 2 miles later the whole car was vibrating and cyclists/walkers were pointing and gaping at us as I endeavored to hide my face in the glove compartment.
We made it to mum's house before getting out to look at said tyre and realising that it had more exploded than become flat. The description "tis fecked" has been used by my mechanic friends who came to help. It suits.

Photo taken by me, blip description by my daughter who was in the car for the trip.