Bug

The word bug has a number of possible interpretations in English. It is usually used colloquially to denote very small animals (such as insects, spiders, snails, slugs, etc). From this meaning stem many others.

1. When used to denote animals, a bug is often and incorrectly used in vernacular to refer to any small, terrestrial arthropod, sometimes taken to include creatures like snails and slugs as well.

Since such insects are often irritating and frustrating (mosquitoes, flies and cockroaches being prime examples of such), this word has also come to refer to something which is irritating or frustrating. For instance, a person might say someone (or a problem) is "bugging" (irritating or frustrating) them.

2. A bug is, however, a precise scientific term that refers to insects of the orders Hemiptera and Homoptera.

3. This term is also often used in a computer context, to refer to a computer program which is frustrating them. The most common usage of this is when a computer program does not perform the function that it is supposed to, while the error in its programming cannot be found. See computer bug.

4. Since it refers to small animals, the term bug is also occasionally (and inaccurately) used to refer to microscopic life forms. Somebody might refer to have caught the "pneumonia bug", for instance.

5. A further extension of this meaning is to small surveillance devices. This can be seen as an extension of the existing meaning of something which is small and irritating (the possible presence of surveillance bugs acts as a detriment to free speech in any context). See bugging.

6. Bug is also the name of two rivers in eastern Europe, the Western and Southern Bug. See Bug (Rivers).

7. In gambling jargon, a bug is a small holdout device that can secretly be attached at the under side of the card table for the purpose of cheating. A card cheat will use a bug to conceal extra cards under the table for further use.

8. In a flight instrument, a bug is a manually positioned marker or pointer which is set to remind the pilot where the needle on the instrument should be pointing. This helps her avoid the need to hold settings in her head, and can then just fly to keep the needle aligned with the bug.