could

could /ˈkʊd/ /kəd/ verb
could
/ˈkʊd/ /kəd/
verb
Britannica Dictionary definition of COULD
[modal verb]
1 
— used as the past tense of can
Usage see: [1]can
2 
a  — used to say that something is possible
b  — used with have to say that something was possible but did not actually happen
c  — used to talk about something that is not possible but that is hoped or wished for
3 
— used in speech to make a polite request or suggestion
4 
— used to say that you are annoyed by something that was or was not done
5 
— used in statements that express a strong emotional reaction
6 
— used in statements that describe something as very bad, good, etc.

could care less

— see 2care

could do with

◊ If you could do with something, you need it or would be helped by getting or having it.