Familiar name for the course taken by a current (5)
I believe the answer is:
neddy
'familiar name for' is the definition.
The definition suggests a singular noun which matches the answer.
'course taken by a current' is the wordplay.
'course' becomes 'n'.
'taken by' means one lot of letters go next to another.
'a current' becomes 'eddy' (eddy is a kind of current).
'n'+'eddy'='NEDDY'
'the' acts as a link.
Can you help me to learn more?
(Other definitions for neddy that I've seen before include "Donkey (colloq.)" , "One of child's 23 ac" .)