From IMDB:
Dolemite is a pimp who was set up by Willie Greene and the cops, who have planted drugs, stolen furs, and guns in his trunk and got him sentenced to 20 years in jail. One day, Queen B and a warden planned to get him out of Jail and get Willie Green and Mitchell busted for what they did to him. However, Dolemite is no stupid man and has a lot of warriors backing him, such as his call girls, who are Karate Experts--and lots more....
According to Moore's obituary in the Los Angeles Times:
The way Moore told it, his introduction to Dolemite came from an old wino named Rico, who frequented a record shop Moore managed in Los Angeles. Rico told foul-mouthed stories about Dolemite, a tough-talking, super-bad brother, whose exploits had customers at the record shop falling down with laughter.
One day Moore recorded Rico telling his stories. Later Moore assumed the role of Dolemite, a character who became the cornerstone of his decades-long career as a raunchy comedian, filmmaker and blues singer.
"What you call dirty words," he often said, "I call ghetto expression."