www.alphadictionary.com

I am looking for a word that means thoroughly and deeply understand-- particularly the significance of something. Per my dictionary, that word would be comprehend. But my sense is that, in practice, comprehend is used interchangeably with understand. E.g. We are so dazzled by Christ's miracles, we fail to comprehend the one-on-one compassion that was a cornerstone of his ministry.

Apperceive?
http://www.alphadictionary.com/bb/viewt ... ion#p49377

This may be a word that requires a modifying adjective to convey the meaning you want. The professor had a deeper comprehension of miracles than I had ever imagined. Apperception in some cases would fit, but it needs to be more common.

Thank you to call_copse and Perry Lassiter.

Via apperception I noticed the per prefix meaning thoroughly. I considered that maybe I needed to coin a word perprehend—to grasp thoroughly. Looking it up in the dictionary, I found instead perpend—to reflect on carefully, which nearly conveys the meaning I want.

The intended use is in a hymn text, and I think I will stick with the familiar even though it doesn't fully convey the meaning I intend.

"Though miracles astound us, please help us comprehend
the one-on-one compassion and care that you extend".

Good to know I may have slightly helped you find the bon mot, even if a little obscure for your requirements!

Judging by the definition given, perpend doesn't equate with apprehend/comprehend. There have been many times I have perpended something only never to comprehend just what it is I'm supposed to apprehend.

Any thoughts on forms? Perpended/perpent, perpension?

Robert Heinlein's work, Stranger in a Strange Land" has the extra-terrestial visitor use the term "grok" with exactly the meaning you are looking for. He ponders on Earth's customs with the intent to understand. The word has made it into dictionaries, but seems in use - so far as I ve seen it - to have lost its intensity as Heinlein used it.