Not a bicycle missing a wheel, but a description of a company, such as a steel maker, that is ultra-sensitive to the business cycle. Some investors enjoy buying and selling cyclicals according to which way they think the cycle is going next. Like any form of market-timing, this is a tricky exercise to get right.
This word is often used in an investment context without its implications being fully appreciated. Most companies and industries are "cyclical" to some degree (although some, like drug companies, are obviously not), but determining the cycle is much more art than science. At our firm we recognize that some companies may be out of favor, perhaps for an extended period. Such companies become "value investments" in time according to our perceptions. Accordingly, many of our investments will be "cyclical" and will have been acquired at times when the cycle for that particular industry may have been starting to improve.