壁垒bìlěi 1.〈古时arch.〉军营的围墙,泛指防御工事。{defensive wall; (in a broad sense) defence works; fortifications; defences} 2.〈比喻fig.〉对立的事物和界限{rival; demarcation line; bounds}: ～分明{be diametrically opposed; be sharply divided}|唯物主义和唯心主义是哲学中的两大～。{Materialism and idealism are two rivalling and diametrically opposed theories in philosophy.}