indiminishable vs. nontrivial

I was writing this paper (forever), and had been trying to find a word that means "cannot be trivialized". I asked both the linguist Mary Ann and another American friend, they thought hard, and gave suggestions, but I was being unreasonably choosy and decided they were not what I wanted. Then as Mary Ann suggested, I went to reference.com, searched a couple words, and finally found "indiminishable", which was exactly what I was thinking about! However, it's hard to not notice that only one dictionary has an entry for the word, which is the Webster's Revised Unabridged Dictionary. I was kind of concerned that since this was the case, quite possibly people would not understand/recognize the word at all.

Later that night I told Mary Ann all about this and she laughed: "We need you foreigners! You use words from the dictonary; we don't use most of them."

Ah, well, I laughed with her, but, in the end, I chose not to use indiminishable as to describe a "cannot be trivialized" situation, for which, I was afraid the word was too sophisticated for. "Nontrivial" instead became my final choice, and Google Scholar is my mute supporter.

Hits returned for "indiminishable": 6
Hits returned for "nontrivial": 298,000