Miranda Lambert -- Happily Singing Divorce Blues

Miranda Lambert fired off another shot at ex-hubby Blake Shelton during a tribute to country legend Loretta Lynn.

It went down Tuesday night at the ACM Honors in Nashville, TN. A post-breakup hot Lambert belted out Lynn's "Rated X," the controversial 1973 track about divorce. Sample lyrics: "Well if you've been a married woman and things didn't seem to work out/Divorce is the key to bein' loose and free so you're gonna be talked about ..."

It's unclear if Lambert picked the song herself, but she does admit it is perfect for her ... right now.

Bad news for Miranda though ... the song is about women empowerment and getting a divorce ... but Blake is the one that filed.