Just outside gym in full view (6)
I believe the answer is:
openly
'in full view' is the definition.
(I've seen this before)
'just outside gym' is the wordplay.
'just' becomes 'only' (synonyms).
'outside' means one lot of letters goes inside another.
'gym' becomes 'pe' (short for Physical Education).
'only' going around 'pe' is 'OPENLY'.
(Other definitions for openly that I've seen before include "Frankly, honestly" , "In public" , "Overtly" , "Without concealment, frankly" , "In frank and candid manner" .)