“The Boss” (Universal) is obviously intended as a comedy vehicle for its star and co-writer, Melissa McCarthy. Unfortunately, whether she’s blithely exposing her rear end to other members of the cast or working through the emotional problems bred during her childhood in an orphanage, McCarthy’s onscreen persona makes a thorough nuisance of herself. And her ill-organized adventures inspire more grimaces than giggles.

At least the starting point of her fictional biography is an institution presided over by a kindly nun, Sister Aluminata (Margo Martindale). However, as McCarthy’s Michelle Darnell swiftly grows into a famed businesswoman, whatever credit with Catholic viewers the script may have racked up is quickly squandered.

An entrepreneur and motivational speaker, Michelle enjoys a Tony Robbins-like ascent, only to suffer a Martha Stewart-style fall when Renault (Peter Dinklage), an ex-lover-turned-competitor, rats on her for insider trading.

Emerging from prison with her fortune confiscated and her reputation ruined, Michelle is given shelter by her long-suffering former secretary, Claire (Kristen Bell), and forms an uncharacteristic emotional bond with Claire’s preteen daughter, Rachel (Ella Anderson).

After attending a meeting of Rachel’s Girl Scouts-like youth organization, the Dandelions, Michelle strikes on an idea for a comeback. She’ll create a for-profit rival to the Dandelions, Darnell’s Darlings, to market Claire’s outstanding brownies.

Dead-end subplots and trashy humor alternate with failed attempts at a more serious tone as Michelle’s scheme advances.

A large-scale catfight, an awkward discussion with Rachel about the fact that Claire’s boyfriend, Mike (Tyler Labine) had a sleepover with Mommy, as well as Michelle’s wholesale lack of modesty are all passed off as fodder for smiles.

The film contains much slapstick violence, pervasive vulgar humor, drug use, an implied premarital encounter and relentless rough and crude language. (O, R)