A structural beam composed of wood laminations or lams. The lams are pressure bonded with adhesives to attain a typical thickness of 1 ½". (It looks like 5 or more 2 X 4's are glued together)
Frank Mayhue, Home Building Manual, Construction Glossary from Home Building Manual, USA 1999. http://www.homebuildingmanual.com/Glossary.htm, (Home Bulid - Amer) {518}
Complete Design, Inc. (Construction Design Specialists), Dictionary of Construction Terminology, Washington, USA 2015. http://completedesign.cc/client-resources/dictiona ry-of-construction-terminology, (Const - Amer) {836}