Wave by one jetty? (5)
I believe the answer is:
ebony
'jetty?' is the definition.
(thesaurus)
'wave by one' is the wordplay.
'wave' indicates an anagram (I've seen 'waving' mean this (letters wave around)).
'by'+'one'='byone'
'byone' is an anagram of 'EBONY'.
(Other definitions for ebony that I've seen before include "Very dark brown" , "Dark hardwood" , "Material for key" , "Heavy hard wood, usually black" , "Hard dark-coloured wood" .)