'Envision ... [= envisage]'── quoted from http://www.ldoceonline.com/dictionary/envisionthe verb 'to envision' not 'to envisage'.
'Envision ... [= envisage]'── quoted from http://www.ldoceonline.com/dictionary/envision
Not a teacher.
Although that is true, envision is used much more widely than envisage. That's just the way it is. Language is funny that way. Words come into favor and disfavor. Good catch, though.
--lotus