Almagest /alˈmə-jest/

1. A great treatise by the Alexandrian astronomer Ptolemy (c.150AD)
2. Extended to other great medieval works on astronomy, etc

• ob.
• OB
• oba
• Obad.
• Obamacare
• ob and sol
• ob-and-soller
• obang
• obangs
• obas
• obbligati
• obbligato
• obbligatos
• obcompressed
• obconic
• obconical
• obcordate
• obdiplostemonous
• obdt
• obduracies
• obduracy
• obdurate
• obdurated
• obdurately
• obdurateness