hair that grows on the lower part of a man's face, especially on the chin and cheeks.

あごや頬に生える（男性の）顔の毛

a person who acts as a false romantic partner to conceal someone else's sexual orientation or true relationship (slang).

（特に同性愛者の）性的指向を隠すために利用される（見せかけの）配偶者・恋人

to confront or defy someone boldly, often in their own domain (e.g., 'to beard the lion in his den').

（特に相手の縄張りや権限のある場所で）大胆に対決する・反抗する

to provide or furnish with a beard; to give someone a beard as part of disguise or appearance.

（人に）ひげを付ける・（見せかけとして）ひげをつけさせる