Ramayana
तदा शैलाग्रशिखरे वामो हनुरभज्यत । ततो हि नामधेयं ते हनुमानिति कीर्त्यते ॥ ४-६६-२४
'You fell on the edge of the mountain peak and your left chin got broken. Since then you are widely known as Hanuman (one who has a wounded chin). ॥ 4-66-24॥
english translation
tadA zailAgrazikhare vAmo hanurabhajyata । tato hi nAmadheyaM te hanumAniti kIrtyate ॥ 4-66-24
hk transliteration by Sanscript