坚实的英文：
firm and substantial
solid

参考例句：

Become more compact; subside
变得更紧实或坚实;下陷

a heart of oak
栎树内层最坚实的心材;[喻]坚强勇敢的人;果断的人

A compact mass of sand
坚实的沙堆

a shrub that displays hardiness.
长得很坚实的灌木

To become compact or solid;cohere.
凝固使坚实或变硬；粘着紧凑

Their sure-footed strides carry them over the high slopes they revere.
他们坚实的脚步就算踏着斜坡也毫不动摇。

Their manner of building secured a certain air of solidity and grandeur.
他们的建筑风格保证了一种坚实壮观的气派。

a skyscraper built on a base of solid rock.
建筑在坚实岩石基础上的摩天高楼

The lathe should be set on a firm base.
车床应安装在坚实的底座上。

The ground has firmed up a lot since it was properly drained.
在适当地排水之后，土地变得坚实多了。

firm是什么意思：
n. 商号；企业
adj. 坚定的；坚固的；强有力的；确定的；坚挺的；严格的
v. （使）坚固；变坚实；加强；使坚定；回升
adv. 坚定地

Are the firm's finances sound?
这家公司的财务状况可靠吗?

His step was not as sharp and firm.
他的脚步不再像从前那样敏捷、坚实。

To become firm or gelatinous; congeal.
凝固凝结或变硬；冻结

substantial是什么意思：
adj. 大量的；实质的；充实的；结实的；牢固的

to hypostatize; to substantiate
使实体化

This is a substantial building.
这是个坚固的建筑物。

The architecture of this house is very substantial.
这座房子的结构很牢固。

solid是什么意思：
adj. 固体的；坚固的；实心的；纯的；一致的
n. 固体，立体图形，立方体

on solid ground
在稳固的基础上

An extremity of a solid is a surface.
立体的边界之一是一个面。

To become compact or solid;cohere.
凝固使坚实或变硬；粘着紧凑