Solutions Billion-year period has 21 entries with similar clues
- 3-letter words
- sho"Billions" airer, for short
- 4-letter words
- nanoBillionth as a prefix
- agesYears and years
- aireSuffix for billion
- 5-letter words
- asianone of nearly five billion
- gmailhow over 1.5 billion people send and receive messages
- yonksYears and years
- 6-letter words
- cyclesRecurring periods of years
- annalsA historical record of events year by year
- 7-letter words
- centuryPeriod of 100 years
- lustrumA period of five years
- recordsNarrative of events year by year
- 8-letter words
- dog-daysHottest period of the year
- 9-letter words
- nanometreOne-billionth of a metre
- millenniaThousand-year periods
- trienniumPeriod of three years
- 10-letter words
- millenniumPeriod of thousand years
- 11-letter words
- quadrenniumFour-year period
- lifeonearthIt's been around for billions of years
- 12-letter words
- quinquenniumFive-year period
- 13-letter words
- indian-summerUnexpectedly warm period late in the year