Adjective 

Definition: lacking perception or consciousness.

Source: http://www.merriam-webster.com/dictionary/insentient

i heard this word one time while watching my favorite show The Walking Dead. The little boy been shot (Carl) and he needed to go through surgery proceeded by Mershall. She asked him if he has done anything surgery like this or if he was a experienced. Mershall responded with “insentient”

Now that i know what this word mean it helps understand that Mershall didn’t have much experience with this type of procedure but he still knows what he was doing. The surgery was a success by the way.