Definition of in pup in US English:

in pup

phrase

  • (of a female dog) pregnant.

    • ‘In the case of a bitch she may turn out to be in pup and you will find yourself saddled with rather more dogs than you can manage.’
    • ‘Now that the reality of Millie being in pup has sunk in, we have been considering the possible combinations and permutations of potential litters.’