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behind; rear
after; later
remainder; the rest
more (e.g. five more minutes); left
also; in addition
descendant; successor; heir
after one's death
「後」 has other readings with different meanings.
あと十分くらいで着くよ。
I'll be there in about ten minutes.
後で電話をしてください。
Please call me later.
あとは私が片付けた。
I tidied up the rest.