The story
Named after Ransom E. Olds, who founded a motor company in 1897. His early companies' names included his surname, and the automobiles were first marketed as Olds automobiles. That collocation was quickly blended informally by the public to produce Oldsmobile, which was soon also used by the company itself. The poker senses of the word refer to the Oldsmobile 98.
Etymology from Wiktionary, CC BY-SA 4.0.