关于"手足情深"的英语表达，综合权威信息整理如下：

核心表达

- "The love between brothers is deep."（兄弟情深）

- "Brothers are as close as hands and feet."（兄弟如手足般亲密）

- "We are brothers as thick as thieves."（我们情同手足）

延伸表达

- "Brotherly love"（兄弟情）

- "As close as kin"（如亲人般亲近）

例句参考

- "My brother Philip died in Wisconsin on Friday while I was in Rome..."（兄弟离世后，作者赶赴罗马）

说明：

以上表达均围绕"兄弟情深"展开，其中高权威性来源（如海词词典、沪江英语学习网）的表述更符合标准英语习惯。若需强调非兄弟关系的深厚情谊，可选用 "as close as kin"等表达。