Gripe about directions when the moon is closest (7)
I believe the answer is:
perigee
'the moon is closest' is the definition.
I can't tell whether this definition defines the answer.
'gripe about directions' is the wordplay.
'about' indicates anagramming the letters.
'directions' becomes 'ee' (the abbreviation for east written twice).
'gripe' anagrammed gives 'perig'.
'perig'+'ee'='PERIGEE'
'when' acts as a link.
Can you help me to learn more?
(Other definitions for perigee that I've seen before include "where orbit's lowest" , "Point of orbit closest to the earth" , "Point where the Moon is closest to the Earth" , "Lowest orbit point" , "Point of closest approach" .)