1) Attachment to a bridle 2) Blind 3) Blinker 4) Bridle attachment 5) Bridle flap 6) Flap on a bridle 7) Less willing to see 8) Screen 9) Winker Found on https://www.crosswordclues.com/clue/blinder
• (n.) One of the leather screens on a bridle, to hinder a horse from seeing objects at the side; a blinker. • (n.) One who, or that which, blinds. Found on http://thinkexist.com/dictionary/meaning/blinder/
Blind'er noun 1. One who, or that which, blinds. 2. (Saddlery) One of the leather screens on a bridle, to hinder a horse from seeing objects at the side; a blinker. Found on http://www.encyclo.co.uk/webster/B/66
a person or thing that blinds. · a blinker for a horse. · a spectacular shot or action in sports, esp. soccer: He played a blinder. Found on https://www.infoplease.com/dictionary/blinder