1. In a sporadic manner
   - sporadically 
2. At regular time intervals

See also: periodical

• range
• range animal
• range hood
• range in
• range of a function
• range of mountains
• range pole
• rangefinder
• rangeland
• ranger
• Rangifer
• Rangifer arcticus
• Rangifer caribou
• Rangifer tarandus
• ranging
• ranging pole
• Rangoon
• rangpur
• rangpur lime
• rangy
• rani
• ranid
• Ranidae
• Ranier
• ranitidine