not easy to see, hear, or understand 不清楚的;不明确的 the motive for this killing is unclear. 谋杀动机不明。 ■not obvious or definite; ambiguous 不明显的,不明朗的;含糊的 their future remains unclear. 他们前途未卜。 ■having or feeling doubt or confusion 怀疑的;茫然的 users are still unclear about what middleware does. 用户对中间件作用仍有疑问。