钉 (dīng/dìng) is a word that can function as both a noun meaning 'nail' or 'tack' and a verb meaning 'to nail' or 'to pin down.' As a verb (pronounced dìng), it describes the action of fastening something with a nail or pin.
他把那幅画钉在了墙上。
tā bǎ nà fú huà dīng zài le qiáng shàng.
He nailed that painting to the wall.
帮我把这块木板钉牢一点。
bāng wǒ bǎ zhè kuài mùbǎn dīng láo yīdiǎn.
Help me nail this wooden board down more securely.
她用图钉把照片钉在了公告栏上。
tā yòng túdīng bǎ zhàopiàn dīng zài le gōnggào lán shàng.
She pinned the photo to the bulletin board with a thumbtack.