The Vietnamese word "cùi chỏ" means "elbow" in English. It refers to the joint in your arm that bends between your upper arm and your forearm.
You can also use "cùi chỏ" in more complex sentences: - "Khi tôi chơi thể thao, tôi thường phải dùng cùi chỏ để bảo vệ mình." (When I play sports, I often have to use my elbows to protect myself.)
In a more figurative sense, "cùi chỏ" can be used in idiomatic expressions relating to being sharp or aggressive in a competitive context, though this usage is less common.