Any language, explain what it means if it’s not English.
For example (as a non-native speaker) I’ve always liked the English word ‘unprecedented’, mostly in the context of fiction. Especially if it paints some entity to be really mystical or wondrous or it’s own never before seen order of magnitude in any way.
Gruntled. It means pleased or contented. It’s the positive form of the much more common “disgruntled”. If someone is caught in the rain, they may be disgruntled about being wet. But you very rarely hear the word “gruntled” used.
Similarly, “whelmed” is a word, which basically means “submerged” or “engulfed”. You can be _over_whelmed by emotion, meaning you were completely overtaken and swept away by the emotion. You can be _under_whelmed by an experience, meaning it failed to fully meet your expectations. But you can also just be whelmed. The experience did exactly what you expected; no more, no less.