Answer: "I drown an eye"
Explanation: A phrase is a word or group of words that function as a single unit in the syntax of a sentence, usually consisting of a head, or central word, and elaborating words.
The phrase from Sonnet 30 by William Shakespeare suggests that the speaker cries when he starts to reminisce is "I drown an eye". The full line 5 is given as: "Then can I drown an eye, unus'd to flow," which indicates that the speaker wept heavily despite that he rarely cries.
The sonnet 30 was first published in 1609 a time wherein young Shakespeare recently arrived the city of London, and broods on life's disappointments which elicits sorrows and pain.