The Collaborative International Dictionary of English v.0.48:

Lecture \Lec"ture\, v. t. [imp. & p. p. Lectured (-t[-u]rd);
   p. pr. & vb. n. Lecturing.]
   1. To read or deliver a lecture to.
      [1913 Webster]

   2. To reprove formally and with authority.
      [1913 Webster]

WordNet (r) 3.0 (2006):

lecturing
    n 1: teaching by giving a discourse on some subject (typically
         to a class) [syn: lecture, lecturing]

Moby Thesaurus II by Grady Ward, 1.0:

44 Moby Thesaurus words for "lecturing":
   autodidactic, coeducational, cultural, debating, declamation,
   demagogism, didactic, disciplinary, edifying, educating,
   educational, educative, elocution, eloquence, enlightening,
   exhortatory, forensics, homiletic, homiletics, hortatory,
   illuminating, informative, initiatory, instructive, introductory,
   oratory, platform oratory, preaching, preceptive, propaedeutic,
   public speaking, pyrotechnics, rabble-rousing, rhetoric,
   self-teaching, speaking, speechcraft, speechification, speeching,
   speechmaking, stump speaking, teaching, tuitionary, wordcraft