Trip Laura organised without Charlie for certain (10)
I believe the answer is:
particular
'certain' is the definition.
(thesaurus)
'trip laura organised without charlie' is the wordplay.
'organised' indicates an anagram.
'without' means one lot of letters goes inside another ('without' can be similar in meaning to 'outside').
'charlie' becomes 'c' (phonetic alphabet: alpha, bravo, charlie etc.).
'trip'+'laura'='triplaura'
'triplaura' with letters rearranged gives 'partiular'.
'partiular' placed around 'c' is 'PARTICULAR'.
'for' is the link.
(Other definitions for particular that I've seen before include "Exceptional" , "Specific" , "Special" , "Meticulous" , "Nice" .)