The definition of asinine is to be silly, stupid or ridiculous. An example of asinine is a foolish prank played on a friend.
In humans, there are twelve thoracic vertebrae and they are intermediate in size between the cervical and lumbar vertebrae; they increase in size going towards the lumbar vertebrae, with the lower ones being a lot larger than the upper.
One of the segments of the spinal column; in human beings there are usually 33 vertebrae: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused into one bone, the sacrum), and 4 coccygeal (fused into one bone, the coccyx).