A feeling of easterly movement (7)
I believe the answer is:
emotion
'a feeling' is the definition.
(I know that emotion is a type of feeling)
'easterly movement' is the wordplay.
'easterly' becomes 'E' (abbreviation for east).
'movement' becomes 'motion' (synonyms).
'e'+'motion'='EMOTION'
'of' acts as a link.
(Other definitions for emotion that I've seen before include "Intuitive feeling" , "A strong instinctive feeling" , "Strong feeling as of love or hate" , "Mental feeling" , "sense" .)