Want solid boat (8)
I believe the answer is:
hardship
'want' is the definition.
(thesaurus)
'solid boat' is the wordplay.
'solid' becomes 'hard' ('hard' can be similar in meaning to 'solid'**).
'boat' becomes 'ship' (I've seen this before).
'hard'+'ship'='HARDSHIP'
(Other definitions for hardship that I've seen before include "distress" , "Severe privation or suffering" , "Difficulty, vicissitude" , "Need" , "Adversity, misfortune" .)