To lean (on or against); to rest or recline against something for support.
疲れてベンチにもたれかかって休んだ。
Tired, I leaned back on the bench and rested.
彼は肩に力を入れすぎず、壁にもたれかかって話した。
He relaxed his shoulders and leaned against the wall while talking.
電車で居眠りをして、前の人にもたれかかってしまった。
I dozed off on the train and ended up leaning on the person in front of me.
To rely on or depend on someone (emotionally, financially, etc.).
彼は困ったときにすぐ親にもたれかかる癖がある。
He has a habit of leaning on his parents as soon as he's in trouble.
会社に長くいる間、同僚に精神的にもたれかかることが増えた。
Over time at the company, he increasingly leaned on colleagues for emotional support.