Word: mainspring
Part of speech: Noun
Syllables: main
spring
Definition: The most important reason for something (Cf. spring "origin of something" (literary) (often in the plural) the springs of her ambition).
Morphemes:
Affix: main
Language: en
PoS: Adjective
Meaning: Of chief or leading importance; prime, principal.
Affix: spring
Language: en
PoS: Noun
Meaning: The source from which an action or supply of something springs.
Etymology Compounds: Affix: springen
Language: enm
Decoded: springen
Meaning: to burst or flow forth, to sprout, to emerge, to happen, to become known, to sprinkle