Complex sentence: In the context of creationists' claims, the word "theory" is used in its vernacular meaning as an imperfect fact or an unsubstantiated speculation, and the purported intent is to discredit or reject the scientific credibility of evolution.
Split into simpler sentences: In the context of the creationist claim, theory is used in its vernacular meaning as an imperfect fact or an unsubstantiated speculation. The purported intent is to discredit or reject the scientific credibility of evolution.