Forces smile awkwardly absorbing pressure (6)
I believe the answer is:
impels
'forces' is the definition.
('impel' can be a synonym of 'force')
'smile awkwardly absorbing pressure' is the wordplay.
'awkwardly' indicates an anagram.
'absorbing' is an insertion indicator.
'pressure' becomes 'p' (abbreviation).
'smile' with letters rearranged gives 'imels'.
'imels' enclosing 'p' is 'IMPELS'.
(Other definitions for impels that I've seen before include "Urges forward" , "Forces, urges to action" , "Drives on in simple way" , "Drives or forces" , "Urges or drives to do something" .)