lacuna

空白（名词）

(noun) An empty space; gap. (NOTE: plural form is usually "lacunae"although "lacunas" is also acceptable)

EXAMPLE: The story of my grandfather's adventuresome life had a curious lacuna between his graduation from college and the establishment of his first successful business.

我祖父的一生充满了冒险故事，不过，在他大学毕业到创办第一家成功企业之间有一段空白，令人好奇。