To my understanding, the phrase “tits up” has always meant “deceased” for a living being and “not working at all” for an inanimate object such as a car. Makes sense. It was always logical to me as referring to a dead animal lying cartoon-style on its back.
I've always loved the phrase and have researched its origins as credibly sourced in military parlance from the WWII era, specifically for upside-down airplanes. It quickly metastasized to the farm community (I found Bessie tits-up in a ditch), and not long after found a new home and even a new meaning on Broadway that I’d previously been unaware of.
It has come to my attention that “tits up” additionally means “with confidence,” the phrase often shouted as a pre-performance confidence-booster among showgirls. Makes sense. With boobs in bustiers that place them aloft for the 42nd Street gawkers, those nervous moments before curtain were just aching for a battle cry and beginning in the 1950s or so, they got one.
Usually, a preponderant acceptance among journalists, artists and the general population is required for a word or phrase to begin meaning something other than it previously has. That didn’t occur with “tits up.” It was simply appropriated by the Broadway performer community and used by them for their purposes irrespective of its broader accepted sense. Broadway said, “We like it, we’re taking it.” I admire that kind of linguistic bravado, especially when its usage is so on-the-money.
“Tits up” refers to posture and attitude on the part of the performer but at the same time seems to lampoon and take back the commercialization of the performer’s sexuality. I like it for both those reasons. The phrase has found new popularity with this contextual usage in the TV series, “The Marvelous Mrs. Maisel,” which is how this meaning previously unknown to me bubbled into my consciousness.
Perhaps the best advice and a true motto for living might incorporate both meanings: “Tits up until you’re tits up.”