noun, noun or participle which takes 'suru'
follow back; following back
Internet slang for the act of following someone on social media in return for them following you. Often used as a noun or with する.
See also: フォローバック
フォロー返しを忘れずにしてくださいね。
Please don't forget to follow back.
彼はいつもすぐにフォロー返ししてくれる。
He always follows back right away.