halve
Halve (verb) means to cut something down to half its original size or amount.
Etymology
The word came into English via Middle English halven, helven, which developed from Old English hilfan, helfan, *hielfan ("to halve, divide in two"). This in turn goes back to Proto-West Germanic *halbijan, from Proto-Germanic *halbijaną ("to halve"), itself from Proto-Germanic *halbaz ("half"). It is cognate with Middle Dutch halven ("to halve") and Middle High German halben, helben ("to halve"), and can be compared with West Frisian helte ("to halve"), Dutch halveren ("to halve"), German Low German halberen ("to halve"), German halbieren ("to halve"), Danish halvere ("to halve") and Swedish halvera ("to halve").