Sea for me strangely frightening (8)
I believe the answer is:
fearsome
'frightening' is the definition.
(synonyms)
'sea for me strangely' is the wordplay.
'strangely' is an anagram indicator.
'sea'+'for'+'me'='seaforme'
'seaforme' is an anagram of 'FEARSOME'.
(Other definitions for fearsome that I've seen before include "Dreadful" , "Terrifying" , "Formidable" , "Frightening, terrible" , "Daunting" .)