[no obj.]speak or write at length or in detail 细说;详述 she expatiated on working-class novelists. 她详细讲述了工人阶级小说家。
派生 expatiation noun 语源
mid 16th cent. (in the sense 'roam freely'): from Latin exspatiari 'move beyond one's usual bounds', from ex- 'out, from' + spatiari 'to walk' (from spatium 'space')