Greek is pesky that way (my usual go-to for this is ἀρετή (areté). You can always take the approach of long ages of classicists - just borrow the word, maybe lightly Anglicized. That has it's own issues, of course, but it does sometimes feel like the best option (I mean, heck, the main idea in the book reviewed here is expressed with a direct borrowing from Latin: the numinous).

As for failings of English, agreed, but it strikes me that every language handles some things better than others. In this case, the single Greek word δεινός (deinós) stresses the similarity of the examples you gave, where English arguably emphasizes their differences better. Flip it around, and Greek's various words for different kinds of love (ἀγάπη (agápē), φιλαδελφία (philadelphía), ἔρως (érōs), and so forth) better highlight that these experiences are different, whereas English "love" better emphasizes what they have in common. There's likely something interesting to be worked out by looking at which concepts a language distinguishes versus smashing together, like the semi-mythical Inuit words for snow or Arabic words for sand.

As you say, moving beyond the need for arbitrary verbal/visual markers for concepts would be awfully convienient (there's that word!).

Cheers,
Jeff