The Collaborative International Dictionary of English v.0.48:

Harbor \Har"bor\ (h[aum]r"b[~e]r), n. [Written also harbour.]
   [OE. herbor, herberwe, herberge, Icel. herbergi (cf. OHG.
   heriberga), orig., a shelter for soldiers; herr army + bjarga
   to save, help, defend; akin to AS. here army, G. heer, OHG.
   heri, Goth. harjis, and AS. beorgan to save, shelter, defend,
   G. bergen. See Harry, 2d Bury, and cf. Harbinger.]
   1. A station for rest and entertainment; a place of security
      and comfort; a refuge; a shelter.
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            [A grove] fair harbour that them seems. --Spenser.
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            For harbor at a thousand doors they knocked.
                                                  --Dryden.
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   2. Specif.: A lodging place; an inn. [Obs.] --Chaucer.
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   3. (Astrol.) The mansion of a heavenly body. [Obs.]
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   4. A portion of a sea, a lake, or other large body of water,
      either landlocked or artificially protected so as to be a
      place of safety for vessels in stormy weather; a port or
      haven.
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   5. (Glass Works) A mixing box for materials.
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   Harbor dues (Naut.), fees paid for the use of a harbor.

   Harbor seal (Zool.), the common seal.

   Harbor watch, a watch set when a vessel is in port; an
      anchor watch.
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The Collaborative International Dictionary of English v.0.48:

Seal \Seal\ (s[=e]l), n. [OE. sele, AS. seolh; akin to OHG.
   selah, Dan. sael, Sw. sj[aum]l, Icel. selr.] (Zool.)
   Any aquatic carnivorous mammal of the families Phocidae and
   Otariidae.
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   Note: Seals inhabit seacoasts, and are found principally in
         the higher latitudes of both hemispheres. There are
         numerous species, bearing such popular names as sea
         lion, sea leopard, sea bear, or ursine seal,
         fur seal, and sea elephant. The bearded seal
         (Erignathus barbatus), the hooded seal (Cystophora
         cristata), and the ringed seal (Phoca foetida), are
         northern species. See also Eared seal, Harp seal,
         Monk seal, and Fur seal, under Eared, Harp,
         Monk, and Fur. Seals are much hunted for their
         skins and fur, and also for their oil, which in some
         species is very abundant.
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   Harbor seal (Zool.), the common seal (Phoca vitulina). It
      inhabits both the North Atlantic and the North Pacific
      Ocean, and often ascends rivers; -- called also marbled
      seal, native seal, river seal, bay seal, land
      seal, sea calf, sea cat, sea dog, dotard,
      ranger, selchie, tangfish.
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WordNet (r) 3.0 (2006):

harbor seal
    n 1: small spotted seal of coastal waters of the northern
         hemisphere [syn: harbor seal, common seal, Phoca
         vitulina]