Does somnambulism need a new definition?

In the discussion titled "How to be sure that your client achieve somnambulism" Art Long made a valid point when he stated "I have been practicing hypnotherapy for 40 years, maybe one day I will get it right- but never once have I had a client sleepwalk... somnambulism = sleepwalking". I started this as a reply to his post, however it seemed to me that it would be better posted as an entirely new discussion.

Art got me to thinking about this. With respect to the natural state of sleep somnambulism does indeed mean sleepwalking, just check any dictionary. But when used in conjunction with the state of hypnosis it seems to me to have an entirely different meaning.

Here is one of the best definitions with respect to the normal sleep state:

Somnambulism

Som*nam"bu*lism\, n. [Cf. F. somnambulisme. See Somnambulation.] A condition of the nervous system in which an individual during sleep performs actions approppriate to the waking state; a state of sleep in which some of the senses and voluntary powers are partially awake; noctambulism.

Webster's Revised Unabridged Dictionary

During hypnosis we refer to the state of somnambulism to indicate a deep state wherein the hypnotized person is able to open his/her eyes, become ambulatory and still remain in a deeply relaxed mental and physical state. This state was first called "artificial somnambulism" by the Marquis de Puységur when he discovered it, and many hypnotists still use the term somnambulism to indicate that state today.

I am sure most of you are already familiar with all of this, but here is my point: shouldn't the definition of somnambulism be updated to reference this singular usage of the word? Shouldn't there be a line added to the above definition that goes something like this:

(2) A deep state of hypnosis wherein the hypnotized person is capable of ambulatory movement, eye opening, and other actions similar to the conscious waking state while remaining in a state of complete physical and mental relaxation.

There probably is a better definition, but you get the idea. In the past, the dictionary has always been updated with new current usages for already defined words. Why can't this be done with somnambulism? Why hasn't it been done already? Is this even a valid point?

Chuck Eubanks
I am but the student, you are the master...