"Vice" is Lambert's first musical release since her fifth studio album, 2014's Platinum. The new tune is written by Lambert, Josh Osbourne and Shane McAnally.
Lambert, 32, has yet to comment on the raw and emotional track — and has yet to reveal whether it's about Shelton — but the lyrics may be a giveaway.
"Another vice, another call, another bed I shouldn't crawl out of. At 7 a.m., with shoes in my hand said I wouldn't do it, but I did it again / And I know I'll be back tomorrow night," she sings.
"Sweet salvation on a dining room table / Waiting on me, where the numb meets the lonely," she continues. "It's gone before it ever melts the ice."
As previously reported, Lambert has been busy in the studio since ending her four-year marriage to Shelton, 40, in July 2015. She's even posted about her music on social media alongside photos of her new boyfriend, Anderson East. Us Weekly exclusively confirmed in December 2015 that they were an item.
"I've been off the road a little bit, so I've been able to kind of go into the creative mode, which is good. I’ve been in Nashville a lot, so I've really been able to write a lot with friends," Lambert told Entertainment Tonight in April. "I'm not rushing trying to get a project done, just taking my time, enjoying it, going to see live music. Just kind of being in it. Just getting creative. That's what I do. That's what I love the most."
Shelton's made his career a priority since their breakup, too. Back in May, he and girlfriend Gwen Stefani released their own heartbreak song — "Go Ahead and Break My Heart." (Stefani, 46, finalized her divorce from Gavin Rossdale in April.) In May, Shelton dropped his new song "She's Got a Way With Words," which is off his latest album, If I'm Honest.
Can't get enough of Us? Sign up now for the Us Weekly newsletter packed with the latest celeb news, hot pics and more!