Originally a bastard was a boy born outside of marriage who had no claim to his father's estate.  In Australia, a bastard is a disreputable person.  This term can be applied fondly.  Now a rat bastard is different animal altogether.

Bathing suit.  Swim suit.  At least Sam didn't use the more graphic Australian term for tight male swimsuits: budgie smugglers.  Budgies are budgerigars, tiny parrots, which are often smuggled out of Australia for sale.  There is only one place in a tight swim suit where a man looks like he's hiding budgies.

Washroom.  Polite Australians say bathroom instead of dunny or toilet.

Wonderful, excellent.

Shut up.  Be quiet.

With typical laconic understatement, Australians will call a very bad experience a bit ordinary.

Swearing, blasting and damning were once similar serious profane actions.  Now blast is considered a more mild exclamation of annoyance.

Exclamation of surprise.  Based on an oath: May God blind me if I tell a lie.  Originally used to emphasize the truth of an amazing statement, now merely an expression of amazement.

Window shade.

Horse blinkers restrict a horse's vision to just what is straight ahead - Americans say blinders.  To walk around with blinkers on is to not see important things.

Australians tend to refer to a house block rather than a street block.

An ordinary man.  An old-fashioned term these days.

The quintessential Australian swear word.  Originally a terrible profanity because the speaker swore By Our Lady, but now used casually.

Rely on other people to do the work.

Can mean an argument, can mean a mistake.  Originated from stack on a blue, meaning, pile onto a policeman (in a blue uniform) and hence start a fight.

Human being.  With a body.  Hopefully.

Really good.  This word has a disputed origin.

A great idea.  Called a brainstorm in America.

Little or nearly no chance.  Australian convict William Buckley escaped and was considered to have no chance of survival.  He lived for thirty-two years with First Nations people which was considered to be an incredible feat of endurance at the time.  If someone is heading for a sure loss, they are said to have "Buckley's or none."

Stag party.  The bridegroom has extreme fun with his mates (friends) before the wedding to celebrate his imminent promise to never do so again.

The dictionary meaning is a physical act, but Aussies use the term casually to mean anything from playing around, to a disreputable man, to an exclamation of annoyance.

Ruined or absolutely exhausted.

When things go bung, they go wrong.

Has the level of professionalism of a small town sports team.

Gossip.  Electronic communication between Australia and other countries was only established in 1872 with the completion of the overland telegraph line. In the meantime, people in the remote Australian countryside which is called the bush seemed to have miraculous ways of sharing news quickly, and this was called the bush telegraph.

Exhausted.  In other contexts, can mean lost.