no rhyme or reason

no rhyme or reason

No particular logic, sense, method, or meaning to a given situation, action, person, thing, group, etc. I've looked over it several times, but there's no rhyme or reason to the document we were sent this morning.
See also: no, reason, rhyme
Farlex Dictionary of Idioms.

rhyme or reason, no

An absence of common sense or reasonableness, as in This memo has no rhyme or reason. Closely related variants are without rhyme or reason, as in The conclusion of her paper was without rhyme or reason, and neither rhyme nor reason, as in Neither rhyme nor reason will explain that lawyer's objections. This term originated in French about 1475 and began to be used in English about a century later. Sir Thomas More is credited with saying of a mediocre book that a friend had put into verse, "Now it is somewhat, for now it is rhyme; whereas before it was neither rhyme nor reason."
See also: no, rhyme
The American Heritage® Dictionary of Idioms by Christine Ammer.

no rhyme or reason

or

no rhyme nor reason

If there is no rhyme or reason or no rhyme nor reason for something, there seems to be no logical or obvious explanation for it. There seems no rhyme or reason behind the pricing of many of these products. I can see no rhyme nor reason for the variance in spelling. Note: You can also say that something happens without rhyme or reason. Symptoms appear and disappear apparently without rhyme or reason. Cuts are being made without rhyme or reason. The only motive is to save money to meet Treasury targets.
See also: no, reason, rhyme
Collins COBUILD Idioms Dictionary, 3rd ed.

there’s no ˌrhyme or ˈreason to/for something

,

without ˌrhyme or ˈreason

no sense or logical explanation: There has been no rhyme or reason to market movements in recent weeks. Changes were being made without rhyme or reason.This phrase comes from Shakespeare’s play As You Like It: ‘But are you so much in love as your rhymes speak?’ ‘Neither rhyme nor reason can express how much’.
See also: no, reason, rhyme, something
Farlex Partner Idioms Dictionary
See also:
  • neither rhyme nor reason
  • rhyme
  • rhyme or reason, no
  • there's no rhyme or reason to/for something
  • rhyme or reason
  • rotten apple spoils the barrel
  • one rotten apple spoils the (whole) barrel
  • one rotten apple spoils the (whole) bunch
  • a bad apple spoils the (whole) barrel
  • bushel
References in periodicals archive
NO RHYME OR REASON? THE Old Almondburian has sent my a rhyme apropros of absolutely nothing whatsoever.
NO RHYME OR REASON?
"He damaged the cars and there is no rhyme or reason for it."
Boozed-up lout says he doesn't remember vandalising 10 cars; NO REASON FOR VANDALISM Thug was high on drugs at time
No Rhyme Or Reason I have been writing poetry now for many years And when last I had a look, I found that I had written so much, Enough in fact to fill a book.
Your Poem
IT DOESN'T make sense that only one poet in the last 15 years has won the Nobel Prize for Literature - there's no rhyme or reason for it.
Poet can corner prize; RESULT!
There's no rhyme or reason." She adds, "We're just trying to keep our inventories low."
Steady performers
And there's a report of a West Side apartment building with a 62 percent rise for no rhyme or reason, although the average market value for Class II properties was 7.96 percent.
City values up over 6%
No Rhyme or Reason? I'VE been reading in the ECHO of late About the rhyming poetry debate I've mulled it over quite a lot Should it rhyme or should it not?
Your Poems
Melvin Smith, 37, said 33-year-old Rhymes and a bodyguard beat him with their "hands and fists for no rhyme or reason" at a sandwich shop near New York's City Hall about six months ago.
PEOPLE