not for a instant

not for a instant

Not for any length of time; not at any point; not at all or in any capacity. Not for a instant did I think this would be a winning ticket, so I was totally gobsmacked to find out I'd won the jackpot! A: "So, did you suspect we were throwing you a surprise party?" B: "No, not for a instant!"
See also: instant, not
Farlex Dictionary of Idioms.

not for a/one ˈminute/ˈmoment/ˈsecond/ˈinstant

(informal) not at all; definitely not: I didn’t think for a minute that he was married. Not for one instant would I ever consider going there on holiday again.
See also: instant, minute, moment, not, one, second
Farlex Partner Idioms Dictionary
See also:
  • not for a/one minute/moment/second/instant
  • not for a second
  • not for a minute
  • not for a moment
  • aint
  • ain't
  • hope not
  • (I) hope not
  • be like ships in the night
  • not by any means