Uncommon and unusual places one entered (7)
I believe the answer is:
special
'uncommon' is the definition.
(similar in meaning)
'unusual places one entered' is the wordplay.
'unusual' indicates an anagram.
'one' becomes 'i' (Roman numeral).
'entered' means one lot of letters goes inside another.
'places' is an anagram of 'specal'.
'specal' enclosing 'i' is 'SPECIAL'.
'and' acts as a link.
(Other definitions for special that I've seen before include "Day's non-menu dish" , "sort of officer" , "Important; particular" , "Designed for a purpose" , "Rare, valuable" .)