| RI | a difficult problem |
|---|---|
| RI | set a riddle |
| RI | explain a riddle |
| RI | speak in riddles |
| RI | pierce many times |
| RI | separate with a riddle, as grain from chaff |
| RI | a canon in which the entrances of successive parts were indicated by cryptic symbols and devices (popular in the 15th and 16th centuries) |
| RI | (often followed by `with') damaged throughout by numerous perforations or holes |
| RI | spread throughout |
| RI | a journey in a vehicle driven by someone else |
| RI | a mechanical device that you ride for amusement or excitement |
| RI | harass with persistent criticism or carping |