Like a computer, is something that can be stimulating (9)
I believe the answer is:
digitalis
'something that can be stimulating' is the definition.
(plant used to treat heart conditions)
'like a computer is' is the wordplay.
'like a computer' becomes 'digital'.
'digital'+'is'='DIGITALIS'
(Other definitions for digitalis that I've seen before include "Drug from foxgloves" , "plant making this drug?" , "Heart drug prepared from foxglove leaves" , "medicinal drug" , "Drug derived from foxglove leaves" .)