The word "however" is used as a conjunction or adverb to indicate a contrast or contradiction. It introduces a statement that differs from or limits the preceding statement, often making a point that qualifies or counters it. For example, if someone says "I want to go out, however, it is raining," they are expressing that while they have the desire to go outside, the rain is a significant counterpoint.
The word "however" comes from the Middle English "how ever," which translates to "in whatever way." It has roots in Old English "hwā" meaning "who" and "ewig" meaning "ever." The usage evolved over time to convey contrast in sentences.