Right, second right, then a left (5)
I believe the answer is:
moral
'right' is the definition.
(similar in meaning)
'second right then a left' is the wordplay.
'second' becomes 'mo' (both are short periods of time).
'right' becomes 'r' (common abbreviation).
'then' means one lot of letters go next to another.
'a left' becomes 'al' (I've seen this in other clues).
'mo'+'r'+'al'='MORAL'
(Other definitions for moral that I've seen before include "Concerned with principles of right and wrong" , "Lesson that can be drawn from a story" , "Behaving ethically" , "Pertaining to right and wrong conduct" , "Underlying significance of a story or event" .)