1 to open out and become flat; to open out sth that was folded 展开；打开；摊开: The sofa unfolds into a spare bed. 沙发打开来就变成一张备用床。I unfolded the letter and read it. 我打开信来看。 [OPP] fold (up) 反义词为fold (up)

2 to become known, or to allow sth to become known a little at a time （使）显露，展现；（逐渐）披露