The word 'cute'...(spoilers)
It's used derisively at least five times in this movie. First after Jeff gets his assignment from Whit, and Whit tells Fisher he's not coming along, Fisher warns him not to cheat him out of his take by saying "And don't get any cute ideas." Then when Whit and Joe surprise him in Acapulco and Jeff says something about them playing cat and mouse with him: Look, I know how you trust people. About as far as you can throw Stephanos here. And that's all right with me,only let's not get so cute about it. And then when he and Kathie meet up at Pyramid Creek: "You're a cute little package to be out walking alone at night." "You're kind of cute yourself to be walking alone any night." Next, when Fisher and Jeff are about to go at it in the cabin and Kathie tells Jeff, "why don't you break his head?" to which Fisher says "Cute." And then finally, after The Kid hooks Joe and Bailey refers to Joe and Kathie as "cute kids".
The previous year, in "The Big Sleep", Carmen Sternwood keeps telling Philip Marlowe that he's "cute". I guess that was a hip slang term at the time?