no 英文高手 here? 請英文高手打一個4-letter word

the sea bares her bosom
to the bright moon
and wave after wave
a butterfly dances to its tune.

注： 這裏任何四個字母組成的排列都叫 word (that is, it is not necessarily an english word).

hint: 每行一個字母

Note: if you have seen the answer somewhere, please do not disclose it.
Thank you.