The term 'Sarcastic in Manner' can be summarized by the crossword solution 'SNARKY, ' which is a six-letter word. SNARKY is an informal adjective that describes someone who is rude, mocking, or sarcastic in their speech or behavior. It is often used to describe someone who speaks in a way that is intended to hurt or insult another person. The term has been around since the late 19th century and is derived from the word 'snark, ' which was first used in Lewis Carroll's poem 'The Hunting of the Snark.'