for; because of; in order to; for the sake of; used to indicate the purpose or recipient of an action

tiger; commonly referred to as 老虎 lǎo​hǔ

to regard as; to consider to be; to act as; to be

(bound form) the ghost of someone eaten by a tiger who then assists the tiger in killing others, as mentioned in the idiom 为虎作伥 wèi​hǔ​zuò​chāng