there's many a slip twixt cup and lip

there's many a slip twixt cup and lip

proverb Even something that one feels confident will succeed can have disastrous problems before it concludes. "Twixt" is a shortening of "betwixt," an archaic form of "between." Everything seems to be going smoothly, but there's many a slip twixt cup and lip, so don't lose focus until we're over the finish line.
See also: and, cup, lip, many, slip, twixt
Farlex Dictionary of Idioms.

There's many a slip 'twixt the cup and the lip

. Prov. Many things may happen to prevent you from carrying out what you intend to do. Bob: Now that I have a contract with a publisher, nothing in the world can stop me from writing this book. Alan: Don't be so sure. There's many a slip 'twixt the cup and the lip.
See also: and, cup, lip, many, slip
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

there is many a slip twixt cup and lip

LITERARY
If you say there is many a slip twixt cup and lip, you mean that plans often go wrong before they are completed so you cannot be sure of what will happen. The building is due for completion in September, but as they say, there's many a slip twixt cup and lip. Note: People sometimes just say there's many a slip, or change the second half of the expression. But there's many a slip twixt now and the eight or nine months it will take the company to design and reopen a new café. Note: `Twixt' is an old-fashioned word meaning `between'.
See also: and, cup, lip, many, slip, there, twixt
Collins COBUILD Idioms Dictionary, 3rd ed.

there's many a slip ('twixt cup and lip)

many things can go wrong between the start of something and its completion; nothing is certain until it has happened. proverb
See also: many, slip
Farlex Partner Idioms Dictionary

there’s ˌmany a ˈslip (’twixt ˌcup and ˈlip)

(saying) (of plans, hopes, etc.) nothing is completely certain until it happens because things can easily go wrong: We should get to London before 7 o’clock, but there’s many a slip ’twixt cup and lip. She aims to get to the top in the company, but there’s many a slip...
The word ’twixt is a short form of the old word betwixt, meaning ‘between’.
See also: many, slip
Farlex Partner Idioms Dictionary
See also:
  • there is many a slip twixt cup and lip
  • there's many a slip
  • There's many a slip 'twixt the cup and the lip
  • twixt
  • village
  • it takes a village
  • teach a man to fish
  • a little knowledge is a dangerous thing
  • a little learning is a dangerous thing
  • the best-laid plans of mice and men
References in periodicals archive
If it's made - and there's many a slip twixt cup and lip - the pairing would be a dramatic late addition to a show already dubbed the most significant in our city for decades.
There's many a slip twixt cup and lip just as there are plenty of obstacles between now and Cheltenham in March, but the classy Flat-raced five-year-old Mijhaar looked a genuine supreme Novices' hurdle prospect with an easy debut win in the 2m1/2f novice hurdle here.
We should look at the old saying, 'There's many a slip twixt cup and lip'."
'Let's remain upbeat and remember the old proverb - there's many a slip twixt cup and lip.'
'It will take a colossal effort to make World Cup but remember the old proverb - there's many a slip twixt cup and lip'