Water fern sick wife found in dockland area (8)

'water fern' is the definition.
(pillwort is a kind of water fern)

'sick wife found in dockland area' is the wordplay.
'sick' becomes 'ill' (synonyms).
'wife' becomes 'w' (abbreviation).
'found in' means one lot of letters goes inside another.
'dockland area' becomes 'port' (ports contain docks).
'ill'+'w'='illw'
'illw' put inside 'port' is 'PILLWORT'.