他的眸中藏着一片海
[tā de móu zhōng zàng zhe yī piàn hăi]
Translated literally this nickname means 'his eyes contain an ocean'. In a metaphorical sense, it implies someone with deep and vast emotions hidden within them which others can hardly read at a glance; they have complex personalities, like the mysterious sea. Alternatively, it can also describe someone who has seen much of the world.