After training Rosa and Leo can type (7)
I believe the answer is:
aerosol
'can type' is the definition.
(type of can)
'after training rosa and leo' is the wordplay.
'after training' is an anagram indicator (train can mean to shape or control).
'and' says to put letters next to each other.
'rosa' put after 'leo' is 'leorosa'.
'leorosa' is an anagram of 'AEROSOL'.
(Other definitions for aerosol that I've seen before include "Sprayer" , "Atomiser" , "Spray producer" , "source of graffiti?" , "Mister" .)