adverb, noun or participle which takes 'suru', na-adjective, noun which may take the genitive case particle 'no'
Describes hair, beards, or fur that is messy, tangled, or sticking out in an untidy way. Often used with 頭, 髪, ひげ, etc.
朝起きたら髪がもじゃもじゃになっていた。
When I woke up in the morning, my hair was all tousled.
彼はもじゃもじゃのひげを生やしている。
He has a scraggly beard.