I would like to have a look how compound adjectives are formed in Quenya. (By "compound" here I mean a compound word consisting of an adjective and a noun, or a noun and a verb).
The majority of examples I have seen are of a structure where the second part can be considered as the principal part of the compound, preceded by a qualifier part (and thus following the logic of their English counterparts). Some examples (without an attempt of completeness):
- aldarembina "tree-meshed"
- fantarkenya "veil-perceiving"
- lungumaite "heavy-handed"
- melumatya "honey-eating"
- menelluin "sky-blue"
- morimaite "black-handed"
- órikuvoite "heart-conceiving"
- sinkahonda "flint-hearted"
- qingatelko "bow-legged"
- rakkalepta "curved-fingered"
- þaurikumba "foul-bellied"
There are however, a couple of examples where the structure is apparently reversed. The two I have been able to find (if there are more I'd love to see them) are
What can be the reason for this apparent irregularity? One reason can be simply euphony: Tolkien may have found the sound of leptafinya preferable to **finyalepta etc. In the case of hendumaika he may have wanted to avoid forming an adjective from an u-dual (*maikahendua?).
It is also possible that these forms are not "irregular" but are in-line with the qualifier-main word structure seen in the first group. If we imagine that Quenya has a family of adjectives ending in -maika e.g. "sharp-eyed" "sharp-eared" "sharp-nosed" (hendumaika, *hlarumaika, *nengwemaika) then the first part does become the qualifier and the adjective fits the pattern. Similarly for leptafinya, one can imagine "sister adjectives" like leptafinya, *talufinya, *lambifinya "smart-fingered, smart-footed, smart-tongued" etc. and again the resulting compounds fit the qualifier - main part pattern.