1describing something sticky or gooey; sticky/glutinous in texture or feel (onomatopoeic).
手にネチネチしたものがついて洗っても取れなかった。
Something sticky was on my hand and wouldn't come off even after washing.
あの飴は溶けてネチネチしているから気をつけて食べてね。
Be careful eating that candy; it has melted and become gooey.
暑くて汗で髪がネチネチして不快だ。
It's hot and my hair is sticky with sweat — it's uncomfortable.
2persisting in a nagging or clinging way; being annoyingly persistent or tenacious in speech or behavior.
彼女は謝っているのに、ネチネチといつまでも文句を言っている。
Even though she apologized, he keeps nagging her persistently.
ネチネチ言うのはやめて、はっきり伝えたほうがいい。
Stop being so nagging; it's better to say it clearly.
彼は別れた恋人のことをネチネチ引きずっている。
He keeps dwelling on his ex-girlfriend in a clingy, persistent way.