| One's significant other | 27 |
| One's special field | 23 |
| One's spiritual being | 25 |
| One's strong point | 22 |
| One's wife, informally | 26 |
| One's wife, slangily | 24 |
| One's youthful side | 23 |
| One, at the Tour de France | 26 |
| One, five or ten, e.g. | 22 |
| One, in Saint-Émilion | 25 |
| One, three or five, e.g. | 24 |
| One, with "a" | 23 |
| One- to ten-yr. investments | 27 |
| One- _____ (short play) | 23 |
| One-act opera by Puccini | 24 |
| One-act Oscar Wilde play | 24 |
| One-act play by O'Neill | 27 |
| One-armed bandit feature | 24 |
| One-armed bandit picture | 24 |
| One-armed bandit's arm | 26 |
| One-armed bandit's gullet | 29 |
| One-armed bandit, briefly | 25 |
| One-billionth of a gig | 22 |
| One-billionth: Comb. form | 25 |
| One-celled creatures (var.) | 27 |
| One-celled microorganisms | 25 |
| One-celled organism (Var.) | 26 |
| One-celled pond dwellers | 24 |
| One-celled protozoa (Var.) | 26 |
| One-celled protozoan (Var.) | 27 |
| One-chevron G.I.'s | 22 |
| One-consonant instrument | 24 |
| One-customer connection | 23 |
| One-customer connector | 22 |
| One-day replacement, often | 26 |
| One-dimensional figure | 22 |
| One-dimensional: Abbr. | 22 |
| One-down four-up card game | 26 |
| One-down, four-up card game | 27 |
| One-eighth of a circle | 22 |
| One-eighth of a fluid ounce | 27 |
| One-eighth of a magnum | 22 |
| One-eighth of an ounce | 22 |
| One-eighth pt. of a V-8 | 23 |
| One-eighties, in slang | 22 |
| One-eighty on the road | 22 |
| One-eighty, informally | 22 |
| One-fifteenth of MMMXV | 22 |
| One-fifth of cinquante | 22 |
| One-fifth of humankind | 22 |
| One-fifth of the Union | 22 |
| One-fifth of trentacinque | 25 |
| One-footer, say, in golf | 24 |
| One-for-one transaction | 23 |
| One-fortieth of a maund | 23 |
| One-fourth of a circle | 22 |
| One-fourth of a shekel | 22 |
| One-half and three-fourths | 26 |
| One-half of a fluid oz. | 23 |
| One-hit wonder of 1984 | 22 |
| One-horned beast, for short | 27 |
| One-horse carriage of India | 27 |
| One-horse-too-many town | 23 |
| One-hoss shay's creator | 27 |
| One-hoss shay's owner | 25 |
| One-hundred-meter sprint | 24 |
| One-hundredth of a balboa | 25 |
| One-hundredth part: Abbr. | 25 |
| One-in-a-million thing | 22 |
| One-inch pencil, for example | 28 |
| One-inch pencils, for example | 29 |
| One-lane highway annoyance? | 27 |
| One-legged ballet pose | 22 |
| One-legged camera stand | 23 |
| One-legged captain of fiction | 29 |
| One-legged literary character | 29 |
| One-legged protagonist | 22 |
| One-liner from the pulpit? | 26 |
| One-liner legend Youngman | 25 |
| One-liner man Youngman | 22 |
| One-man band performances | 25 |
| One-man Broadway hit of 1989 | 28 |
| One-man show about Capote | 25 |
| One-man show set in 1975 | 24 |
| One-masters of Mideast | 22 |
| One-million connection | 22 |
| One-million connectors | 22 |
| One-millionth of a meter | 24 |
| One-name R&B artist | 23 |
| One-name singer of the 1960s | 28 |
| One-name soccer legend | 22 |
| One-named 1970's singer | 27 |
| One-named 2009 Oscar winner | 27 |
| One-named 90's singer | 25 |
| One-named actor from Tel Aviv | 29 |
| One-named art deco designer | 27 |
| One-named art deco master | 25 |
| One-named Barbadian singer | 26 |
| One-named British pop singer | 28 |
| One-named costume designer | 26 |