Flexible reply to "Which one?" (6)
I believe the answer is:
either
(Other definitions for either that I've seen before include "Choice of two" , "could be one of two" , "offered a choice" , "Each of two; moreover" , "One of two alternatives" .)
I believe the answer is:
either
(Other definitions for either that I've seen before include "Choice of two" , "could be one of two" , "offered a choice" , "Each of two; moreover" , "One of two alternatives" .)