noun, の adjective
A small theory is some idea you have that you put on paper. Perhaps it's an idea about life, that you write in the form of a novel?
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.
I seriously love this novel. This is legit.
Dad is glowing with pride because his novel is selling well, huh?
“Here, wipe your tears and nose,” Koichi said, ripping off a page of the novel that he'd been reading and handing it to Kristen.