Source : Webster's Revised Unabridged Dictionary (1913)

Teach \Teach\, v. t. [imp. & p. p. {Taught}; p. pr. & vb. n.
   {Teaching}.] [OE. techen, imp. taughte, tahte, AS. t?cean,
   imp. t?hte, to show, teach, akin to t[=a]cn token. See
   {Token}.]
   1. To impart the knowledge of; to give intelligence
      concerning; to impart, as knowledge before unknown, or
      rules for practice; to inculcate as true or important; to
      exhibit impressively; as, to teach arithmetic, dancing,
      music, or the like; to teach morals.

            If some men teach wicked things, it must be that
            others should practice them.          --South.

   2. To direct, as an instructor; to manage, as a preceptor; to
      guide the studies of; to instruct; to inform; to conduct
      through a course of studies; as, to teach a child or a
      class. ``He taught his disciples.'' --Mark ix. 31.

            The village master taught his little school.
                                                  --Goldsmith.

   3. To accustom; to guide; to show; to admonish.

            I shall myself to herbs teach you.    --Chaucer.

            They have taught their tongue to speak lies. --Jer.
                                                  ix. 5.

   Note: This verb is often used with two objects, one of the
         person, the other of the thing; as, he taught me Latin
         grammar. In the passive construction, either of these
         objects may be retained in the objective case, while
         the other becomes the subject; as, I was taught Latin
         grammar by him; Latin grammar was taught me by him.

   Syn: To instruct; inform; inculcate; tell; guide; counsel;
        admonish. See the Note under {Learn}.

Teaching \Teach"ing\, n.
   The act or business of instructing; also, that which is
   taught; instruction.

   Syn: Education; instruction; breeding. See {Education}.

Source : WordNet®

teaching
     n 1: the profession of a teacher; "he prepared for teaching while
          still in college"; "pedagogy is recognized as an
          important profession" [syn: {instruction}, {pedagogy}]
     2: a doctrine that is taught; "the teachings of religion"; "he
        believed all the Christian precepts" [syn: {precept}, {commandment}]
     3: the activities of educating or instructing or teaching;
        activities that impart knowledge or skill; "he received no
        formal education"; "our instruction was carefully
        programmed"; "good teaching is seldom rewarded" [syn: {education},
         {instruction}, {pedagogy}, {educational activity}]