Heart's Desire, Earnest Wish
noun, verbal noun, の adjective
What your thoughts request inside your head, nonstop like a crazy person, are your heart's desires.
ねんがん
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
ついに、念願のマイホームを手に入れました！
Finally, I've got my long-awaited dream home!
ニュース見た？原田選手、念願の１部リーグ入りだって！
Did you see the news? Harada made it to the top league as he always wanted!
やったー！ついに念願の彼氏ができたよー！
Yay! After all this waiting, I finally got a boyfriend.