ADJECTIVE (3)

1. pertaining to the surface of a body part;
- Example: "a drug for topical (or local) application"
- Example: "a topical anesthesia"

2. of or relating to or arranged by topics;
- Example: "a detailed record on both a chronological and a topical basis"

3. of interest at the present time;
- Example: "a topical reference"
- Example: "a topical and timely study of civil liberty"

The Collaborative International Dictionary of English v.0.48:

Topical \Top"ic*al\, a. [Cf. F. topique, LL. topicus, Gr. ?. See
   Topic, n.]
   1. Of or pertaining to a place; limited; logical application;
      as, a topical remedy; a topical claim or privilege.
      [1913 Webster]

   2. (Rhet. & logic) Pertaining to, or consisting of, a topic
      or topics; according to topics.
      [1913 Webster]

   3. Resembling a topic, or general maxim; hence, not
      demonstrative, but merely probable, as an argument.
      [1913 Webster]

            Evidences of fact can be no more than topical and
            probable. --Sir M. Hale.
      [1913 Webster]

WordNet (r) 3.0 (2006):

topical
    adj 1: pertaining to the surface of a body part; "a drug for
           topical (or local) application"; "a topical anesthesia"
    2: of or relating to or arranged by topics; "a detailed record
       on both a chronological and a topical basis"
    3: of interest at the present time; "a topical reference"; "a
       topical and timely study of civil liberty"