Related Clues:

• Being no longer neutral, lost one's head and died
• Sidney was not neutral over the editor
• Was partisan
• Like a die
• Allied oneself (with)
• One- -- (biased)
• One-__: biased
• One-___ victory (rout)
• Follower of lop
• Like all polygons
• Favoured a team, perhaps
• Gave support to the team?
• Allied oneself (with one party)
• Showed solidarity (with)
• Supported fourth faction?