Stop using space bar function (7)
I believe the answer is:
embargo
'stop' is the definition.
(I know that embargo is a more specific form of the action stop)
'space bar function' is the wordplay.
'space' becomes 'em' (in typography, a space as wide as a letter 'm').
'function' becomes 'go' (synonyms).
'em'+'bar'+'go'='EMBARGO'
'using' acts as a link.
(Other definitions for embargo that I've seen before include "Trade stoppage" , "Restraint - prohibition" , "Official prohibition as on trade" , "Prohibit" , "Government order imposing a trade barrier" .)