simple past tense and past participle of graduate
"She graduated from college last summer after studying engineering for four years."
In plain English: To graduated means to finish your studies and officially become part of a higher level, such as moving from middle school to high school or graduating college.
"She graduated from high school last summer and started college in September."
taking place by degrees
"The team's celebration was graduated, starting with quiet applause and building to a roaring cheer as the final goal was scored."
In steps.
"The audience began to cheer, and then gradually erupted into a roar of applause as each team member stepped forward."