俨然:
1.adv. just like
e.g. 那个小男孩一本正经地开始迈起步子,俨然是个小士兵。
That boy starts stepping with a poker face, and is just like a little soldier.
2.adj. orderly, solemn (only used in written language)
e.g. 土地平旷,屋舍俨然,有良田美池桑竹之属。
The field was flat and the houses were orderly, there were fertile farmyards, beautiful pools , mulberries and bamboos as well.
——From 《桃花源记》, a famous classical Chinese poem written by ancient poet 陶渊明.