This word consists of the kun'yomi readings for all the kanji. You haven't learned these readings for 之 or 実 yet though, so here's a mnemonic to help you:
If you get too close to a clownfish, it will hide inside its stinging anemone and shout, "YOU DON'T KNOW ME (のみ)! It's true, you don't know this clownfish, but you want to. I guess all of them are afraid of strangers though... how will you know me if you don't give me a chance, clownfish?!
Nemo and his family are fish called clownfish.