what-d'you-call-him/-her/-it/-them

what do you call (someone)/it

Used to indicate a person or thing whose name is not known or can't be remembered. "What do you" is often condensed into informal contractions such as "whaddya" or "what d'you," and the phrase is sometimes hyphenated in writing. I heard old what do you call him is back to teaching the course again next week. I ran into whaddya-call-her from next door at the grocery store this morning. He keeps playing that dang what-d'you-call-it on the computer all day.
See also: call, what
Farlex Dictionary of Idioms.

ˈwhat-d’you-call-him/-her/-it/-them

,

ˈwhat’s-his/-her/-its/-their-name

used instead of a name that you cannot remember: She’s just gone out with old what-d’you-call-him. Have you heard from what’s-her-name from the library recently?
Farlex Partner Idioms Dictionary
See also:
  • waddaya
  • whaddya
  • what do you call (someone)/it
  • flow
  • babysitter test
  • card
  • carded
  • carding
  • how-d'ye-do
  • nummers