To adhere to; to stick to something so that it does not come off.
このテープはよくくっつくから、重い箱でも大丈夫だ。
This tape sticks well, so it's fine even for heavy boxes.
焼き海苔がご飯にくっついてしまった。
The roasted seaweed stuck to the rice.
窓に水滴がくっついている。
Droplets are clinging to the window.
To stay close to someone or something; to go along with or cling closely to someone.
赤ちゃんは母親にくっついて眠っている。
The baby is asleep snuggled up against its mother.
子どもが公園でずっと私にくっついて離れない。
The child clings to me in the park and won't let go.
新しい社員は先輩にくっついて仕事を覚えている。
The new employee is learning the job by shadowing a senior.
To become involved with someone; to become intimate or thick with someone (can imply forming a close or romantic relationship).
最近あの二人はいつも一緒で、くっついているみたいだ。
Those two have been together a lot lately; it seems like they're an item.
彼女は職場の先輩とくっついてしまったようだ。
It seems she has gotten involved with a senior at work.
余計な人にくっつかれたくないから、一人で出かけた。
I went out alone because I didn't want someone unnecessary clinging to me.