1. make a sudden flinching movement out of fear or pain: "he blenched and struggled to regain his composure"
2. become pale:"a shudder shook the boy's frame and his face blenched"
Word OriginOld Englishblencan ‘deceive’, of Germanic origin; later influenced by blink. blench (sense 2) is a variant of blanch, although in practice the two senses are very difficult to disambiguate.
