English is replete with idiomatic expressions featuring numerical values, including dozens pertaining to the number one alone. Here’s a list of most (if not all) of the idioms in the latter category.
1. all in one breath: said of something spoken excitedly without pause
2. all in one piece: safely
3. all rolled up in one: combined
4. all-in-one: with all required features
5. as one: as if a group were one entity
6. at one with: in agreement or solidarity with another
7: do (someone) one better: do something that is an improvement on what someone else has done
8. for one thing: said to introduce one of two or more reasons (though the phrase might follow the statement)
9. for one: a qualifier expressing that someone represents an example
10. hole in one: said of a significant achievement, in reference to achieving a goal in golf with a single hit of the ball
11. if it’s not one thing: part of a saying (with the rest, “it’s another (thing)” often not said but implied) expressed when one is exasperated by the latest in a series of inconveniences
12. in one ear and out the other: said of advice or information that is not heeded or retained
13. in one fell swoop: all at once or within a short period
14. it’s been one of those days: said when multiple things have gone wrong in succession
15. it’s just one of those things: said of something unfortunate that must be accepted
16–17. look after/take care of number one: said in reference to focusing on one’s own safety or concerns over that of others
18. not one iota: not even a bit
19. number one: oneself (see “look after number one”)
20. on the one hand: from one point of view (sometimes paired with “on the other hand”)
21. one and all: everyone
22. one for the (record) books: said of a significant achievement
23. one good turn deserves another: an expression about the importance of reciprocity
24. one-hit wonder: an artist who achieves only one commercial success
25–26. one heck/hell of a (something): a reference to someone being markedly bad or good at something
27. one in a million: rare or unique, often said about someone with a distinctive quality
28–29. one jump/step ahead: said of someone who anticipates or innovates
30. one man’s meat is another man’s poison: something one person likes may not be suitable for another person
31. one-night stand: an activity or encounter that lasts only one night
32. one-note: said of something lacking variety
33. one of a kind: unique
34. one of the boys: someone accepted into or part of a group
35. one of these days: said of an expected event that will occur someday or soon; also, sometimes expressed as a threat, with the consequence implied but not stated
36. one of those things: said of something unwelcome but inevitable
37. one person’s trash is another person’s treasure: something of no value to one person may be valuable to another
38. one that got away: a missed opportunity
39. one-track mind: said of someone with a single-minded focus
40. one-trick pony: someone or something with only one distinguishing feature, skill, or talent
41. one up on: said of having an advantage over someone
42. one way or another: somehow
43. square one: the starting point of developing something or solving a problem (often in the phrase “back to square one”)
44. the one and only: said of something unique
45. there is more than one way to skin a cat: more than one procedure will work or more than one solution is available
Other number-oriented idioms, including those that mention the number one but in which the focus is on another number, such as “Two heads are better than one,” will follow in a later post.
Surely you should include all the expressions using “once” to have a more complete list?
Jason:
I deliberately refrained from including idioms with once, as well as single and first, because of the overwhelming number of items that would result; that’s also why I limited this post to idioms about just the first number. Follow-up posts will pertain to other numbers and other counting forms.