/ ˈweðə(r); NAmE / conjunction
1.
used to express a doubt or choice between two possibilities :
He seemed undecided whether to go or stay.
It remains to be seen whether or not this idea can be put into practice.
I asked him whether he had done it all himself or whether someone had helped him.
I'll see whether she's at home (= or not at home) .
It's doubtful whether there'll be any seats left.
➡ note at if
2.
used to show that sth is true in either of two cases :
You are entitled to a free gift whether you accept our offer of insurance or not.
I'm going whether you like it or not .
Whether or not we're successful, we can be sure that we did our best.
••
WORD ORIGIN
Old English hwæther , hwether , of Germanic origin; related to German weder neither.