Bone found in Dublin Bay oddly ignored (4)
I believe the answer is:
ulna
'bone' is the definition.
(I know that ulna is a bone)
'dublin bay oddly ignored' is the wordplay.
'oddly ignored' indicates alternate letters (letters in odd-numbered positions removed).
'dublin'+'bay'='dublinbay'
The alternating letters of 'dublinbay' are 'ULNA'.
'found in' is the link.
(Other definitions for ulna that I've seen before include "Thinner of two long bones in forearm" , "Bone from the human elbow" , "part of arm" , "Inner bone of the human forearm" , "Car document; ticket book" .)