Possibly. I can also imagine other verbal adjectives like melíte or iríte (to get desire into the picture); or the imperfect participle melila.
Even melmea is a possibility; cf. Hungarian where the adjective "in love" is formed from the noun "love".

+Tamas Ferencz I believe ite ending is approaching participle in expressing an inherent quality, 'apt to do smth.' So, melíte can mean no more that 'amorous, one who falls in love indiscriminately'.

+Александр Запрягаев again, you may be right. But then again Tolkien assigned a specific verbal adjective to mean "apt to do sthing" which is -ula. But indeed elsewhere he is talking about -ite having a sort of permanent quality.
Then also we might have the simple *melia.

BTW if you have a look at the list of verbal adjectives I compiled at docs.google.com - Quenya verbal adjectives and other derived forms I also assigned permanent meanings to the -ite forms

In Estonian one finds armu- (inf. armuda, armuma) "to fall in love", past active participle armunud "(fallen) in love". What would, say, *melúna mean in Quenya in light of PE22 contents?

That is an interesting proposition. page 114 certainly implies that verbs in u often had (or acquired) an inceptive meaning, so indeed -*melu- could mean "fall in love"; as for the passive, the form liruima on p 111, and the fact that -ina remains unchanged in verbs ending in -a, suggests that the form would be *meluina.
Then on pp 135-136 he discusses -u verbs again from a CE perspective, and here he states that it is really the suffixes lu, ru, nu that carry the inceptive meaning, and he cites the forms thillu, thilnu "shine out, appear" which could suggest that our verb would rather look like *mellu, melnu.

Thoughts?

*melme-sse-a 'en-amour-ed', 'being in love', as meneldea < *menel-(es)se-a 'being in heaven' (Átaremma IIb--V)?

I thought of that but melme isn't a noun that one can physically be "in".

+James Coish Not physically, but the locative can also be used figuratively, cf. hara máriesse 'stay in happiness', sangiessemman 'in our necessities'.

+James Coish is the English "love" a noun that we can be physically "in"?

By the way: I needed 'in love' before, and that time expressed it as mel(m)inqua, with KWA 'full', as 'love-filled'.

+Александр Запрягаев that is also a good solution. Now let someone say Quenya vocabulary is restricted! :)

Tamas it isn't and that's what confuses me. Maybe I take things to literal.

+James Coish well sure, one needs a fair amount of tinkering with sense and synonyms to translate something to Quenya, at least quite often that's the case

+Tamas Ferencz Goodness, I've forgotten the most straightforward way of expression, melmerwa/arwa melmeo!