LONG definition: having considerable linear extent in space. See examples of long used in a sentence. Wide may be used instead of long when referring to a left-to-right horizontal dimension, or to a horizontal dimension shorter than that described as long (for example, a river that is wide and long). long, yearn, hanker, pine, hunger, thirst mean to have a strong desire for something. long implies a wishing with one's whole heart and often a striving to attain. yearn suggests an eager, restless, or painful longing. hanker suggests the uneasy promptings of unsatisfied appetite or desire. To strongly crave or desire something is to long for it. No matter how healthful your diet is, you'll still occasionally long for chocolate, cookies, and cake. The adjective long describes something that stretches over a large distance. LONG Building Technologies provides building automation, security systems, commercial HVAC service and parts, as well as building analytics. This disambiguation page lists articles associated with the title Long. If an internal link incorrectly led you here, you may wish to change the link to point directly to the intended article. Copy and paste Long Dash Symbol (—). Check Alt Codes and learn how to make specific symbols on the keyboard. LONG definition: 1. continuing for a large amount of time: 2. being a distance between two points that is more than…. Learn more. Long is used in expressions such as all year long, the whole day long, and your whole life long to say and emphasize that something happens for the whole of a particular period of time. 1. A long time: This won't take long. 2. Linguistics A long syllable, vowel, or consonant. 3. One who acquires holdings in a security or commodity in expectation of a rise in price.