Source : Webster's Revised Unabridged Dictionary (1913)

Activate \Ac"ti*vate\, v. t.
   To make active. [Obs.]

Source : WordNet®

activate
     v 1: put in motion or move to act; "trigger a reaction"; "actuate
          the circuits" [syn: {trip}, {actuate}, {trigger}, {set
          off}, {spark off}, {spark}, {trigger off}, {touch off}]
     2: make active or more active; "activate an old file" [ant: {inactivate}]
     3: make more adsorptive; "activate a metal"
     4: aerate (sewage) so as to favor the growth of organisms that
        decompose organic matter [syn: {aerate}]
     5: make (substances) radioactive