Hire store will founder, I suppose (9)
I believe the answer is:
theoriser
'will founder i suppose' is the definition.
I can't tell whether this definition defines the answer.
'hire store' is the wordplay.
'hire store' can be anagrammed to 'THEORISER'.
Though, I am unsure how the anagram is indicated.
Can you help me to learn more?
(Other definitions for theoriser that I've seen before include "One who has convictions" , "one who speculates" , "he thinks" , "speculator" , "One who reasons" .)