Jetty accommodates one adventurer (7)
I believe the answer is:
pioneer
'adventurer' is the definition.
(I know that pioneer is a type of explorer)
'jetty accommodates one' is the wordplay.
'jetty' becomes 'pier' (I've seen this before).
'accommodates' indicates putting letters inside.
'pier' going around 'one' is 'PIONEER'.
(Other definitions for pioneer that I've seen before include "Lead the way" , "Ripe one (anag.)" , "One who blazes the trail for others" , "Research leader" , "take the lead" .)