Often used metaphorically to signify a principal source of something, not just a starting point. His grandmother's stories were the fountainhead of his passion for writing.
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Figurative Speech
Commonly found in figurative speech, implying a wellspring of endless inspiration or knowledge. This library is a veritable fountainhead of historical works.
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Academic Context
Particularly apt for academic settings where it may describe the origin of schools of thought. Plato's Academy was the fountainhead of Western philosophy.