British & Australian, American & Australian

someone or something that has suddenly become very popular, but may not remain popular for long.

Role-playing games are suddenly the flavour of the month.

• a rake-off
• a rap across the knuckles
• a rap on the knuckles
• a rap over the knuckles
• a rap sheet
• a rat fink
• a rat race
• a raw deal
• a ray of sunshine
• are all over
• a red cent
• a red eye
• a red herring
• a red-letter day
• a reign of terror
• a Renaissance man
• a rent boy
• are someone all over
• are something all over
• a revolving door
• Are you a man or a mouse?
• argue the toss
• argy-bargy
• a rich seam
• a ringside seat