myx-, myxo- +

(Greek: slime, mucus; used often in biomedical nomenclature)

myxovirus
Any of a group of RNA-containing viruses, including those that cause influenza, typically having an affinity for certain mucins (glycoproteins found especially in the secretions of mucous membranes) and causing agglutination of red blood cells.
paramyxovirus
One of a group of RNA viruses that are responsible predominantly for acute respiratory diseases and are usually transmitted in an airborne manner.

The paramyxoviruses include the agents of mumps, measles (rubeola), RSV (respiratory syncytial virus, which mainly afflicts children), Newcastle disease, parainfluenza, Sendai virus and Hendra virus.

Many of the paramyxoviruses cause disease in animals; such as, canine distemper and turkey rhinotracheitis.