The Collaborative International Dictionary of English v.0.48:

I \I\ ([imac]), pron. [poss. My (m[imac]) or Mine
   (m[imac]n); object. Me (m[=e]). pl. nom. We (w[=e]);
   poss. Our (our) or Ours (ourz); object. Us ([u^]s).]
   [OE. i, ich, ic, AS. ic; akin to OS. & D. ik, OHG. ih, G.
   ich, Icel. ek, Dan. jeg, Sw. jag, Goth. ik, OSlav. az', Russ.
   ia, W. i, L. ego, Gr. 'egw`, 'egw`n, Skr. aham. [root]179.
   Cf. Egoism.]
   The nominative case of the pronoun of the first person; the
   word with which a speaker or writer denotes himself.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Ours \Ours\ (ourz), possessive pron.
   See Note under Our.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

We \We\ (w[=e]), pron.; pl. of I. [Poss. Our (our) or Ours
   (ourz); obj. Us ([u^]s). See I.] [As. w[=e]; akin to OS.
   w[imac], OFries. & LG. wi, D. wij, G. wir, Icel. v[=e]r, Sw.
   & Dan. vi, Goth. weis, Skr. vayam. [root]190.]
   The plural nominative case of the pronoun of the first
   person; the word with which a person in speaking or writing
   denotes a number or company of which he is one, as the
   subject of an action expressed by a verb.
   [1913 Webster]

   Note: We is frequently used to express men in general,
         including the speaker. We is also often used by
         individuals, as authors, editors, etc., in speaking of
         themselves, in order to avoid the appearance of egotism
         in the too frequent repetition of the pronoun I. The
         plural style is also in use among kings and other
         sovereigns, and is said to have been begun by King John
         of England. Before that time, monarchs used the
         singular number in their edicts. The German and the
         French sovereigns followed the example of King John in
         a. d. 1200.
         [1913 Webster]