solesole /səʊlsoʊl/ adjectiveadj [only before a noun]1a sole thing or person is the only oneThe company’s sole business is software that blocks spam.
He became the sole owner of an investment management firm.
2a sole responsibility, duty, right etc is one that is not shared with anyone elseDerek has sole responsibility for sales in this region.
When he retired, he left his partner in sole control.