mạt cưa mướp đắng

Etymology
From.

Earliest extant attestation of this figure of speech is in the poem "Tuơng phùng (Chance Meeting)" in  (Collection of poems in our nation's language in the (1470 - 1497 CE)) (Vol. 3, folio 58b):

Noun

 * 1)  deceiver, swindler, fraudster, scammer
 * 2) * 2010, Nguyễn Văn Thịnh, Thời Bi Tráng (A Woeful and Majestic Time), Chapter 8
 * Cùng phường mạt cưa mướp đắng cả! – Ông giáo cười khẩy:… Dù Diều hâu hay Bồ câu, đều phải vì nước Mỹ, lợi thì vơ vào, bất lợi thì phải nhả ra thôi!
 * "They're all deceivers and swindlers!" Sniggered the Professor: "Whether hawks or doves, they must all act in the United States' interests; if they could profit, they'd hog everything; if they could not profit, they'd spit it all out!"
 * "They're all deceivers and swindlers!" Sniggered the Professor: "Whether hawks or doves, they must all act in the United States' interests; if they could profit, they'd hog everything; if they could not profit, they'd spit it all out!"