動詞 expound:

1. add details, as to an account or idea; clarify the meaning of and discourse in a learned way, usually in writing
   同義詞：elaborate, lucubrate, expatiate, exposit, enlarge, flesh out, expand, dilate
2. state
   同義詞：set forth, exposit

1. Our teacher expounded his views on education to me at great length.
   我們的老師向我詳細講述了他的教育觀點。
2. He expounded the reasons why he did it.
   他闡述了他做這件事的理由。

ex.pound

v.（動詞）
ex.pound.ed,ex.pound.ing,ex.pounds
v.tr.（及物動詞）
To give a detailed statement of; set forth:
詳述：詳細敘述；闡明：
例句：
expounded the intricacies of the new tax law.
闡明新稅法的復(fù)雜性

To explain in detail; elucidate:
解釋：詳細解釋；闡述：
例句：
The speaker expounded the approach of positive thinking.See Synonyms at explain
發(fā)言人闡述了反動思潮的出現(xiàn)參見 explain

v.intr.（不及物動詞）
To make a detailed statement:
陳述：做詳細的陳述：
例句：
The professor was expounding on a favorite topic.
教授正在對一個令人喜歡的話題詳加陳述

來源：
Middle English expounden
中古英語 expounden
from Anglo-Norman espoundre
源自 英法語 espoundre
from Latin expônere
源自 拉丁語 expônere
ex- [ex-]
ex- [前綴，表.…之外.]
pônere [to place] * see apo-
pônere [完全認定] *參見 apo-

【引伸】
expound.er
n.（名詞）