noun

• (Canada, US) Any scavenging bird, such as the American black vulture (Coragyps atratus) or the turkey vulture (Cathartes aura).
• (colloquial, derogatory, slang, often preceded by "old", the "old buzzard") In North America, a curmudgeonly or cantankerous man; an old person; a mean, greedy person.
  "Perhaps the crusty old buzzard loved his only child more than anyone had given him credit for all these years — maybe even more than he himself had realized."
• (archaic) A blockhead; a dunce.
  "1640, George Herbert, Jacula Prudentum; or, Outlandish Proverbs, Sentences, etc., in The Remains of that Sweet Singer of the Temple George Herbert, London: Pickering, 1841, p. 142, An old man’s shadow is better than a young buzzard’s sword."
• (golf) Synonym of double bogey.

noun

• (euphemistic) A bastard.