Unlucky is used a few different ways. It can describe things that are thought to bring bad luck, such as unlucky number, or it can describe people that have been unsuccessful in an endeavor or that been met with unfortunate circumstances. Hapless deals with the latter. This pitiable adjective is defined as “luckless” or “unfortunate,” and it most commonly describes people that simply can’t catch a break. The lamentable status of a hapless individual is reflected in the adjectives that regularly appear near it, such as poor (meaning unfortunate), helpless, hopeless, and miserable (the poor hapless fool was utterly hopeless!).

The adjective unreasonable describes ideas or behaviors that are not guided by reason or sound judgement. It can also refer to things that exceed sensible expectation (a list of unreasonable demands) or that are exorbitant or unconscionable (the prices were unreasonable). Things that are irrational are utterly illogical and may border on the absurd. An irrational fear is one that is not grounded in logic or reason and is therefore unlikely to come true. In mathematics, irrational is used to describe a number that cannot be exactly expressed as a ratio of two integers, such as pi.

An effect is something that is produced by an agency or cause, usually more or less immediately and directly: Exposure to the sun had the effect of toughening his skin. A repercussion is an effect or result, often indirect or remote, of some event or action. Effect carries no ominous baggage or negative associations on its own; it correlates with the word cause as a neutral term describing a relationship between events. But repercussion, which more often appears in the plural, is commonly used to talk about undesirable developments.