dyad /dīˈad/

1. A pair of units treated as one
2. A bivalent atom, radical, or element (chem)

dyadˈic adjective

• pianists
• piano
• piano accordion
• piano accordions
• pianoforte
• pianofortes
• Pianola®
• pianolist
• pianolists
• piano nobile
• piano organ
• piano organs
• piano-player
• piano-players
• piano roll
• piano rolls
• pianos
• piano-school
• piano-schools
• piano stool
• piano stools
• piano wire
• piano wires
• piarist
• piarists