Here is a word that I have read over many times before because I can guess the meaning by the context. But when I came across it in “The Missing Three-Quarter” in The Greatest Adventures of Sherlock Holmes, I decided to look it up instead of just skimming by.

Sardonic – grimly mocking or cynical

Usage: Holmes is telling Watson how he was following a suspect. He was on a bicycle, and the suspect was in a carriage. “The carriage stopped, the doctor alighted, walked swiftly back to where I had also halted, and told me in an excellent sardonic fashion that he feared the road was narrow, and that he hoped his carriage did not impede the passage of my bicycle.”