Younger relative and I tan remarkably in Mediterranean country (5-5)

'younger relative' is the definition.
(child of a niece or nephew)

'i tan remarkably in mediterranean country' is the wordplay.
'remarkably' is an anagram indicator.
'in' is an insertion indicator.
'mediterranean country' becomes 'Greece' (Greece is next to the Mediterranean).
'i'+'tan'='itan'
'itan' anagrammed gives 'atni'.
'atni' placed within 'greece' is 'GREAT-NIECE'.

'and' is the link.