Intention is willing (i.e., trying to do, seeking a goal).
'Conation' is a synonym for intention.
Montessori (1917) discussed 'the will' in terms of its manifestation as motivation, that is, intelligent choices to move towards a goal.
The whole external expression of the will is contained in movement: whatever action man performs, whether he walks, works, speaks or writes, opens his eyes to look, or closes them to shut out a scene, he acts by "motion" .... Therefore the will is not a simple impulse towards movement, but the intelligent direction of movements.
There can be no manifestation of the will without completed action; he who thinks of performing a good action, but leaves it undone; he who desires to atone for an offense, but takes no step to do so; he who proposes to go out, to pay a call, or to write a letter, but goes no farther in the matter, does not accomplish an exercise of the will. To think and to wish is not enough. It is action which counts. (pp. 170-171, italics added)