I'm a complete beginner in Chinese, but I was under the impression that 內勁 or neijin(g) translates to internal strength? That term might be more familiar to CMA practitioners. 内力 is literally internal power, but I have no clue how common it is to say it that way.
Good point, I use 'internal energy" as Chi and "internal power" as Jing and Fah Jing as "transfer" or "projection." These terms and definitions are the most commonly used when I speak with those who I know that practice CMA. Per neijin my understanding and usage is along the lines of Wikipedia's explanation http://en.wikipedia.org/wiki/Nei_Jing
Also include the term Neijia, as well http://en.wikipedia.org/wiki/Neijia
I use these term in this fashion, and no longer use "internal strength" as it is not used with those I know in the CMA and is not as commonly used in my readings.
I also do this to be more accurate and inline with the above reasons, and so that there is no confusion with previous posts on internal arts that was discussed on this forum sometime ago. I am using these terms, as stated above, as a demarcation from my previous conversations on internal strength.
Well that is how I use those terms.