Synonyms for Commence:

n.

bring about, catalyze, start-off, trigger. enter, kick off, set-to, take on, launch, open. arise. appear. commence (noun)
set out, begin, start out, set about, get, embark on, lead off, start, start up.
start (noun)
study at begin, enter upon.

v.

begin (verb)
initialize, develop, emerge, germinate, stem, start, originate, inaugurate, prepare, sprout, hatch, introduce, initiate, bud, embark, create, induct, begin, birth, dawn, conceive, undertake, spring, form.
change (verb)
begin, start, lead off.
originate (verb)
generate, institute, invent, produce.
start action (verb)
kick off, enter upon, initiate, lead off, originate, launch, embark on, begin, inaugurate, open, arise.

Other synonyms:

start-off. launch. appear. arise. enter. open. approach
set about.
begin
enter upon, kick off, open, trigger.
enter
lead off.
start-up
start up.

Usage examples for commence

  1. Be that as it may, I regretted abandoning it, for I felt assured that in doing so our difficulties and trials would commence – Expedition into Central Australia by Charles Sturt
  2. A little while spent there, and then I had every reason to believe that my life- work in China would commence – A Retrospect by James Hudson Taylor
  3. I have from the first felt sure that the writer, when he sits down to commence his novel, should do so, not because he has to tell a story, but because he has a story to tell. – Autobiography of Anthony Trollope by Anthony Trollope