Assume a spot without pressure (5)
I believe the answer is:
adopt
'assume' is the definition.
(synonyms)
'a spot without pressure' is the wordplay.
'spot' becomes 'dot' (I've seen this before).
'without' indicates putting letters inside ('without' can be similar in meaning to 'outside').
'pressure' becomes 'p' (abbreviation).
'dot' going around 'p' is 'dopt'.
'a'+'dopt'='ADOPT'
(Other definitions for adopt that I've seen before include "Take responsibility for" , "Espouse" , "Formally approve" , "Take into one's family" , "Choose as one's own" .)