A memorial plaque for celebrated missionary Jim Elliot is to be re-worded because of offensive language, Wheaton College has announced.

Elliot was one of five American missionaries killed trying to evangelize the Waorani, a native Ecuadorian people group, in 1956.

He and fellow slain missionary Ed McCully became friends while attending Wheaton College together. They were killed alongside colleagues Nate Saint, Peter Fleming and Roger Youderian on January 8, 1956, when they were attacked by members of the Waorani at the Curaray River.  

Although the five men died, their widows later went on to convert some of the Waorani - including their husbands' killers - through their own missionary efforts. 

The college announced on Monday that a 1957 plaque honouring the missionaries is to be replaced following a review of its language.

New wording on the plaque will remove reference to "savage Indians" and replace the pejorative word 'Auca' with 'Waorani', the name the indigenous group calls itself.

The new language is based on the recommendations of a task force put together by the college to review the original wording. 

The college said it was important that the plaque honour the missionaries while also "respecting the Waorani people with whom they shared the gospel of the love of Christ."

"In the 64 years since the College received this gift, we have continued to grow in our understanding of how to show God's love and respect to people from every culture," said Wheaton College President Philip Ryken.

"We have also learned much more about God's ongoing work among the Waorani. We welcome this opportunity to ensure that we tell this unforgettable story in ways that reflect the full dignity of people made in the image of God."