drijfveer (zn):
The most important spring in a mechanical device (especially a clock or watch); as it uncoils it drives the mechanism
mainspring
drijfveer (zn):
The cause or intention underlying an action or situation, especially in the phrase `the whys and wherefores'
wherefore, why
drijfveer (zn):
A rational motive for a belief or action
ground, reason
Via: Ensyns.nl
Via: Memodata.com