| Period of advancing glaciers | 28 |
| Period of bacchanalia? | 22 |
| Period of contemplation | 23 |
| Period of economic growth | 25 |
| Period of effectiveness | 23 |
| Period of financial weakness | 28 |
| Period of focusing on oneself | 29 |
| Period of frigid temperatures | 29 |
| Period of future bliss | 22 |
| Period of gradual decline | 25 |
| Period of great glaciation | 26 |
| Period of great growth | 22 |
| Period of great prosperity | 26 |
| Period of greatest success | 26 |
| Period of human benightedness | 29 |
| Period of imminent danger | 25 |
| Period of increased births | 26 |
| Period of investor confidence | 29 |
| Period of little change | 23 |
| Period of low activity | 22 |
| Period of major fighting | 24 |
| Period of marked improvement? | 29 |
| Period of metalwork advances | 28 |
| Period of most activity | 23 |
| Period of mourning in Judaism | 29 |
| Period of one's prime | 25 |
| Period of play in curling | 25 |
| Period of powerlessness | 23 |
| Period of radio silence | 23 |
| Period of rapid growth | 22 |
| Period of rationing (abbr.) | 27 |
| Period of rationing: Abbr. | 26 |
| Period of self-indulgence | 25 |
| Period of service duty | 22 |
| Period of slow development | 26 |
| Period of success on Broadway | 29 |
| Period of suspended activity | 28 |
| Period of the Cenozoic Era | 26 |
| Period of the Crusades | 22 |
| Period of the first dinosaurs | 29 |
| Period of time in Spain | 23 |
| Period of time, in astronomy | 28 |
| Period of unbridled activity | 28 |
| Period of watchful attention | 28 |
| Period of watchfulness | 22 |
| Period that appears endless | 27 |
| Period that unifies calendars | 29 |
| Period to find out more | 23 |
| Period too long to measure | 26 |
| Period when things go poorly | 28 |
| Period with little rainfall | 27 |
| Period with nothing to do | 25 |
| Period, in Web addresses | 24 |
| Periodi-cal, for short | 22 |
| Periodic activity of snakes | 27 |
| Periodic chart data: abbr. | 26 |
| Periodic dairy aisle offering | 29 |
| Periodic growth, as funds | 25 |
| Periodic Halloween sight? | 25 |
| Periodic income, in Paris | 25 |
| Periodic Pacific disruption | 27 |
| Periodic produce outbreak | 25 |
| Periodic table datum, briefly | 29 |
| Periodic table developer | 24 |
| Periodic table entry (Abbr.) | 28 |
| Periodic table info: Abbr. | 26 |
| Periodic table listing | 22 |
| Periodic table listings | 23 |
| Periodic table period? | 22 |
| Periodic table's no. 10 | 27 |
| Periodic weather disruption | 27 |
| Periodic White House event | 26 |
| Periodic-table component | 24 |
| Periodic-table entries | 22 |
| Periodic-table listing | 22 |
| Periodic-table listing: Abbr. | 29 |
| Periodical accessed by a URL | 28 |
| Periodical changers: Abbr. | 26 |
| Periodical of haute couture | 27 |
| Periodical opinion piece | 24 |
| Periodical output: Abbr. | 24 |
| Periodical table abbr. | 22 |
| Periodical, informally | 22 |
| Periodicals, for short | 22 |
| Periodonist's concern | 25 |
| Periodontist's concern | 26 |
| Periodontist's concerns | 27 |
| Periodontist's deg. | 23 |
| Periodontist's focus | 24 |
| Periodontist's grp. | 23 |
| Periodontist's org. | 23 |
| Periodontists' grp. | 23 |
| Periodontists' org. | 23 |
| Periods for Aries and Taurus | 28 |
| Periods for geologists | 22 |
| Periods immediately before | 26 |
| Periods in prison, e.g. | 23 |
| Periods just past midnight | 26 |
| Periods just past sunset | 24 |
| Periods of development | 22 |