a boy so precious the world doesn't deserve him. he has the voice of an angel and can dance really well, not to mention that his beauty is unique and he's also really funny, often mischievous. whoever gets to spend time with him will feel their heart warming up and wanting to break free from their ribcage, accompanied by the desire to give him the whole universe. his full name is lee donghyuck, member of korean group NCT.
person 1: i heard a voice so pure and crystalline i thought i had died and was mere footsteps away from heaven
person 2: nah, you just probably heard donghyuck sing, his voice is the epitome of angelic
person 1: oh well, i still hope his voice will be the first thing i hear when i die.
Donghae is a name for the "East Sea" or "Sea of Japan." It's a body of water that essentially connects the two countries (that historically don't get along).
Hence: Donghae (when used in weeb slang) means "After a slow burn (a long waiting period) your OTP finally get together." It's meant to be used as more of a sound effect or to punctuate.
Weeb 1: IT TOOK ED 64 EPISODES TO GET WITHWINRY! FUCK! WE'RE FINALLY HERE!
Weeb 2: DONGHAE!!!
Dongsaeng is a Korean word describing a family or friendshiprelationship. It is used to refer to one's younger sibling or a close friend that is younger than oneself.
"I promised my dongsaeng I'll treat her for dinner if she did well on her test."
(Although the above statement is a command, 'dongsaeng' acts as a form of endearment like 'little brother' or 'little sister'. In other words: "Lil' bro, how about a cup of coffee for your big bro?")