Source : Webster's Revised Unabridged Dictionary (1913)

Log \Log\, v. t. [imp. & p. p. {Logged}; p. pr. & vb. n.
   {Logging}.] (Naut.),
   To enter in a ship's log book; as, to log the miles run. --J.
   F. Cooper.

Logging \Log"ging\, n.
   The business of felling trees, cutting them into logs, and
   transporting the logs to sawmills or to market.

Source : WordNet®

logging
     n : the work of cutting down trees for timber

log
     v 1: enter into a log, as on ships and planes
     2: cut lumber, as in woods and forests [syn: {lumber}]
     [also: {logging}, {logged}]

log
     n 1: a segment of the trunk of a tree when stripped of branches
     2: large log at the back of a hearth fire [syn: {backlog}]
     3: the exponent required to produce a given number [syn: {logarithm}]
     4: a written record of messages sent or received; "they kept a
        log of all transmission by the radio station"; "an email
        log"
     5: a written record of events on a voyage (of a ship or plane)
     6: measuring instrument that consists of a float that trails
        from a ship by a knotted line in order to measure the
        ship's speed through the water
     [also: {logging}, {logged}]

logging
     See {log}