It topped contenders including "double-vaxxed", "AUKUS" and "net zero" to become the Australian National Dictionary Centre's 2021 word of the year.

The centre traced the winning word back to May, when ACTU secretary Sally McManus said: "We don't have a vaccine rollout, we have a vaccine strollout."

"There were many words relating to the pandemic," ANDC director Amanda Laugesen said.

"They reflected our experience of the pandemic as an international event through much shared pandemic language, as well as our own unique experiences and responses."

Dr Laugesen described "strollout" as a uniquely Australian word that took off globally, landing in publications such as the Washington Post.

The words "double-vaxxed", the vaccine "rollout" and jab "hesitancy" were among contenders making the shortlist alongside "AUKUS" and "net zero".

"Some of the other themes we've traced through our short list include our regional security and the ongoing climate emergency," Dr Laugesen said.

Language around the climate and environment had also gained traction over recent years.

"(It) will probably continue to be a strong theme in the new words we track," Dr Laugesen said.

Australia's 2020 word of the year was "iso".

Australian Associated Press