impenetrable

英 [ɪm'penɪtrəb(ə)l] 美[ɪm'pɛnɪtrəbl]

• adj. 不能通过的；顽固的；费解的；不接纳的

1. not admitting of penetration or passage into or through;

"an impenetrable fortress"

"impenetrable rain forests"

2. permitting little if any light to pass through because of denseness of matter;

"dense smoke"

"heavy fog"

"impenetrable gloom"

3. impossible to understand;

"impenetrable jargon"