iffy

The word "iffy" is an adjective used to describe something that is uncertain, questionable, or not entirely reliable. It can also imply a degree of doubt or suspicion. The origin of the word is somewhat obscure, though it is believed to have emerged in the late 19th or early 20th century.

"Iffy" is often used in informal contexts to express reservations about a situation, plan, or statement. For example, one might say a weather forecast is "iffy" if it's not very confident, or that a business deal seems "iffy" if there are reasons to be concerned about its outcome. It can also refer to something that is not in perfect condition, such as an "iffy engine" that sometimes sputters.

The term carries a sense of vagueness and can be a polite way of indicating that something is not quite right or that there are potential problems. While not considered formal vocabulary, "iffy" is widely understood and used in everyday English conversation.