A friend of mine said in a photo of me, my eyes looked very 萌(meng2).
My dictionary defines 萌 as;
萌 méng （动）
sprout; bud; germinate
But apparently in this context it means "cute", "kawaii".
How is this so?
From the wikipedia article:
目前「萌」大多使用在二次元裡，如果遇到刻意將現實世界（三次元）的人套用到二次元的審美的情況，也有可能用到「萌」。 不過這種狀況十分稀少，因為三次元的人通常難以構成萌屬性。 現在「燃え」在中文界解作萌的相對詞，是對熱血的喜愛。
There are two main theories of the origin:
One is that 「燃え」(to burn, describing a reaction to something attractive) is a homophone in Japanese with「萌え」(to sprout), so Japanese Anime enthusiasts decided the latter was a better (perhaps more poetic?) way to describe this kind of reaction.
One is that「燃え」and「萌え」got switched because the IME would put「萌え」 first.
In any event, it seems clear that this use of
萌 comes from Japanese anime, and it originally described a reaction to a beautiful woman. Now, it can refer to anything loveable.
萌 = cute/lovely is an adoption from Japanese usage (wikipedia).
It is widely used as such in Mainland China, Taiwan, Hong Kong pop culture media (website, forum, publication), especially related to comics, animation, and video game.
It is popping up in main stream media from time to time, but only in entertainment section.
The word 萌 méng, defined as "sprout; bud; germinate" has the connotations of a "baby" plant.
Another term for "cute" (at least in American English) is "baby-faced."
To liken someone to a 萌 is to refer to him as a "baby" (face), and therefore cute.
萌is more than cute or lovely,it performs a way to express the feelings about something is too adorable that you can't resist.
It is like the one you described makes green shoots grow out of your heart.
It is extended by Japanese phrase 萌え。
萌's common usage in chinese phrase:
It's just a Japanese word. Chinese cartoon/manga/anime/game/ACG fans borrowed it.
Many modern words in Chinese come from Japanese, such as "物理" and "化学".