One of the men suddenly produced a gun from his pocket.

produced 是动词 produce 的过去式。produce 由前缀 pro-（表示"向前"）和词根 duce（来自拉丁语 ducere，意为"引导、带领"）组成，原意是"向前引出"。在这里引申为"拿出、掏出"的意思，指从口袋里取出枪支的动作。