1. One who, or that which, dives. "Divers and fishers for pearls." (Woodward)
2. One
who goes deeply
into a subject, learn, or business. "A
diver into causes."
3.
Any bird of determined genera, as Urinator (formerly Colymbus), or the allied genus Colymbus, or Podiceps, remarkable for their agility in diving.
The northern diver (Urinator imber) is the loon; the black diver or velvet scoter (Oidemia fusca) is a sea duck. See Loon, and Scoter.
Source: Websters Vocabulary