Sentence:  One saint's day in mid-term a certain newly appointed suffragan-bishop came to the school chapel, and there preached on “The Inner Life.”  He at once secured attention by his <WSD>informal</WSD> method, and when presently the coughing of Jarvis […] interrupted the sermon, he altogether captivated his audience with a remark about cough lozenges being cheap and easily procurable. 
Meaning of the word marked with <WSD> tags:  Not formal or ceremonious.