What's the difference between actor and tragedian?

Actor

Definition:

(n.) One who acts, or takes part in any affair; a doer.
(n.) A theatrical performer; a stageplayer.
(n.) An advocate or proctor in civil courts or causes.
(n.) One who institutes a suit; plaintiff or complainant.

Example Sentences:

(1) Hollywood legend has it that, at the first Academy awards in 1929, Rin Tin Tin the dog won most votes for best actor.
(2) The talent base in the UK – not just producers and actors but camera and sound – is unparalleled, so I think creativity will continue unabated.” Lee does recognise “massive” cultural differences between the US and UK.
(3) Three experiments in person perception were conducted to investigate the conditions under which naive observers label an actor as aggressive and to ascertain how this label affects the reactions of the observers to the actor.
(4) Along with a lengthy list of cameos, Girls actor Gaby Hoffmann and Party Down star Martin Starr appear as former Neptune High classmates new to the Veronica Mars universe.
(5) Notably, while the lead actors were all professionals, most of the cast members and musicians came from Providência itself.
(6) She says he wants his actors to be in a "second state", instinctive, holding nothing back.
(7) American Horror Story is a paean to the supernatural whose greatest purpose is letting washed-up actors and pop stars chew the scenery on the way to winning awards .
(8) Like Morton, Sevigny is an actor who holds nothing back from the camera.
(9) While the Spielberg of popular myth is Mr Nice Guy, Lean was known as an obsessive, cantankerous tyrant who didn't much like actors and was only truly happy locked away in the editing suite.
(10) The committee's findings include that the attacks were not extensively planned by the perpetrators; the intelligence community did a good job of warning about the risk of an attack but a bad job of summarizing the attack when it happened; the state department screwed up by not beefing up security at the mission; nobody blocked any military response; and that the Obama administration was slow to produce a paper trail but was generally not a sinister actor in the episode.
(11) Although it never really has a sense of fun and burns with ill-focused anger, The Paperboy represents a kind of triumph, surely, even if it's just in getting such high-profile actors to do such low-down deeds.
(12) Mr Bae stars in a popular drama, Winter Sonata, a tale of rekindled puppy love that has left many Japanese women hankering for an age when their own men were as sensitive and attentive as the Korean actor.
(13) An actor dressed like one of the polar bears that figure in Coke ads limped up, wearing a prosthesis on one paw, a dialysis bag and tubing.
(14) Ridley and Boyega are part of a swathe of actors – also including Girls' Adam Driver and Ingmar Bergman regular Max von Sydow – who were confirmed by studio Disney in May.
(15) Braff will direct and play the lead role of a father, actor and husband struggling to find his identity.
(16) The actor and his fee have become the news story, and there's no credible reason to believe that Downey is a HTC fan.
(17) Three female actors, including former Bond girl Olga Kurylenko , are rumoured to be in the running for the lead female role in the upcoming sequel to superhero reboot Man of Steel, reports Variety .
(18) The two groups of actors in this new development--the risk assessors and the strain designers--need the same platform of understanding from the field of microbial ecology, and a number of specific areas which may now be approached by modern technology deserve particular attention.
(19) It appeared Dunaway and Warren Beatty had an envelope containing a card naming a previous award won by La La Land, prompting visible hesitation between the two veteran actors before Dunaway went ahead and named La La Land.
(20) According to this explanation, aspects of the situation are phenomenologically more salient for actors, whereas characteristics of the actor and his behavior are more salient for observers.