Phrases starting with the letter: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Previous word: lumbricoid
Next word: lumhead
Definition of: lumen
(l ′mən) noun plural ·mens or ·mi·na (-mə·nə)
′mən) noun plural ·mens or ·mi·na (-mə·nə) 
1. A passageway or opening. 
2. Biol. The inner cavity of a cell or tubular organ, as a gland. 
3. Physics A unit for measuring luminous flux, equal to the flow through a steradian from a uniform point source of one international candle. [<L, light]
 
				
Comment about this word, ask questions, or add new information about this topic: