noun
backseater; unwanted advice giver
Derogatory internet slang for someone who posts unsolicited instructions or criticism in the comments of online videos or live streams, especially Let's Play content.
配信のコメント欄に指示厨が湧いてうざい。
Backseaters popping up in the stream's comments are annoying.
あの指示厨はいつもプレイヤーに細かく指示を出す。
That backseater always gives detailed instructions to the player.
厨 is a derogatory suffix derived from 厨房 (kitchen), used in internet slang to label someone as an annoying or immature person obsessed with something.
Compound of 指示 (instruction) and the derogatory internet slang suffix 厨 (derived from 厨房, 'kitchen', used for annoying or immature people).