- (formal)
something that supports or forms the basis of an argument, a claim, etc. 加强，巩固，构成（…的基础等） the theoretical underpinnings of the study 研究的理论基础
- (specialist)
the act of supporting a wall and making it stronger by putting metal, concrete (= a hard building material), etc. under it; the metal, concrete, etc. that supports the wall The only way to save the building is through extensive underpinning. 保存建筑物的唯一方法是广泛的支撑。