Every time Polly Hammerton hears the "R-word", she feels like she has been punched in the stomach.

“For me, it’s a physical feeling,” the 23-year-old triplet and speech pathologist told 9news.com.au.

Then comes the “frustration and disappointment” that strangers, comedians or even close friends would use the word "retard" or "retarded" at all.

“People who are affected by it often have a disability themselves. For those who don’t, it’s difficult to see how it hurts,” she said.

Polly Hammerton, 23, with her brothers Healy (L) and Pierce (R) (Supplied) (Supplied)

Growing up in rural Victoria with a brother who has multiple disabilities, Ms Hammerton learnt to grow a thick skin following a tirade of verbal abuse.

Her brother Pierce has Down syndrome and was later diagnosed with Autism and bipolar disorder.

“It has always been a unique set up in our household. My brother and I have been passionate about learning how to communicate with Pierce,” she said, explaining her natural transition into a career in speech pathology.

The triplets have grown up with a special bond. (Supplied) (Supplied)

Last May, the family received devastating news when Pierce was diagnosed with aggressive Acute Lymphoblastic Leukaemia – a common childhood cancer.

He was 22.

“It was a huge surprise – and it was difficult for him to communicate what his symptoms were. That was hard for all of us to work out what was going on,” Ms Hammerton said.

Coming to terms with her brother’s terminal prognosis, she is campaigning to end the use of an “exclusive, offensive and derogatory” word and open a conversation she claims is often brushed aside.

She describes the word "R-word" as one which has evolved "from an unbiased medical description to merely a pejorative term".

Last year, Pierce was diagnosed with aggressive Acute Lymphblastic Leukaemia. (Supplied) (Supplied)

“While there are similar words, this one has hung around because there has been a period of time where it was used in both scientific and slang contexts,” Ms Hammerton said.

The origin of the word dates back to the 1400s and is derived from the Latin word ‘retardare’, meaning to hinder or slow. The first time it was printed in an American newspaper was in 1704, but it wasn’t until the 1960s when it was first used to label people with intellectual disability.

Only in recent decades has the word become a socially-acceptable reference and today, Ms Hammerton believes the “reverse card” has been dealt.

“The word soon rapidly became a term of derision, when it was frequently interchanged with words such as idiot or stupid,” she wrote in an article that has since attracted a huge response online.

Like Pierce, she wrote those who are susceptible are often “defenceless”.

Over the years, Polly and Healy have been passionate about learning how to communicate with their brother Pierce. (Supplied) (Supplied)

“Often the most common argument is that people don’t mean it in a ‘disabled way’ – they mean it in a ‘stupid’ or ‘messed up’ way,” Ms Hammerton wrote.

“But the meaning remains the same.”

Ms Hammerton told 9news.com.au she “wants people to realise the relationship this has to people with disability and the personal pain that it can cause”.

Last July, Polly and her brother Healy raised $15000 for the Leukaemia Foundation. (Supplied) (Supplied)

After her article was shared on social media, she received messages of support from all corners of the world.

“A lot of people can relate to this,” Ms Hammerton said.

“I acknowledge that there will always be people who continue to use the word. But even some of my friends have told me they’ll be making a change."

She urges people to "think about who you’re talking to, the language that you use and why you use it".

Facing a future without her beloved brother by her side, Ms Hammerton describes him as “inspirational, unique, positive, challenging and persistent”.

“What Pierce has shared with us is anything but 'retarded',” she said.

“I know he would be grateful for what I’m doing.”