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.
The sacrum and coccyx are uniquely shaped. Medical professionals often abbreviate the levels (vertebrae) of the spinal column. For example, the seven cervical vertebrae are C1, C2, C3, C4, C5, C6 and C7. The thoracic levels are T1, T2, and T3 through T12. Similarly the lumbar levels are L1 through L5 (or L6). The sacrum is simply S1.