Two words
May be 2 words combined (inter+duo) If not obvious, probably incorrect
du.o NUM 1 2 NOM P M CARD
du.o NUM 1 2 NOM P N CARD
du.o NUM 1 2 VOC P M CARD
du.o NUM 1 2 VOC P N CARD
du.o NUM 1 2 ACC P M CARD Early
du.o NUM 1 2 ACC P N CARD
duo -ae o, secundus -a -um, bini -ae -a, bis NUM [XXXAX]
2 - (CARD answers 'how many');
inter PREP ACC
inter PREP ACC [XXXAX]
between, among; during; [inter se => to each other, mutually];
*

Credits:
This, our local install of the popular standby Whitaker's Words, is possible thanks to the resurrection of the venerable project at William Whitaker's Words, where you will also find extensive documentation. The corresponding GitHub repository is where you can submit issues about missing forms and analyses.
This web interface by Walter M. Shandruk.