Learned via the grapevine

• "I ___ It Through the Grapevine"
• Picked up, in a way
• Picked up aurally
• Learned of
• Been told
• Gossiper's word
• Took evidence from

Wiktionary Word definitions in Wiktionary
alt. (en-past of: hear ) vb. (en-past of: hear )

WordNet Word definitions in WordNet
adj. detected or perceived by the sense of hearing; "a conversation heard through the wall"