What is the etymology of 一人前?


I found this word today, and I thought it was pretty interesting. I read it in
the context of "becoming and adult", or "coming of age", but I'd like to know
the etymology of it. I could only find definitions for the word itself, not
its origins. At first blush it looks like "one person before/ahead", but it
also seems like `人前` can mean a portion of food. "One person's portion of
food"? (Perhaps someone is now big enough to have an adult's portions?)




The etymology is itinin + mae. I could say more about mae, but more likely you
are wondering why it means this.

The key is understanding that -mae is a suffix which means: 1) an amount or
portion suitable for X; sannin-mae: a serving such as food) suitable for three
people 2) emphasises ones attributes or functionality; otoko-mae "manly", ude-
mae "skill, prowess"

Source (seems to be popular lately):
[Daijirin](http://dic.yahoo.co.jp/dsearch?enc=UTF-8&p=%E5%89%8D&dtype=0&dname=0ss&stype=1&index=118332200000&pagenum=1),
[Daijisen](http://dic.yahoo.co.jp/dsearch?enc=UTF-8&p=%E5%89%8D&dtype=0&dname=0na&stype=1)

In itinin-mae, the sense is "a person of ability and skills", hence an adult.
This is the second meaning given above. Depending on the context, the first
meaning is also possible: a serving (such as food) suitable for one person.




The etymology is itinin + mae. I could say more about mae, but more likely you
are wondering why it means this.

The key is understanding that -mae is a suffix which means: 1) an amount or
portion suitable for X; sannin-mae: a serving such as food) suitable for three
people 2) emphasises ones attributes or functionality; otoko-mae "manly", ude-
mae "skill, prowess"

Source (seems to be popular lately):
[Daijirin](http://dic.yahoo.co.jp/dsearch?enc=UTF-8&p=%E5%89%8D&dtype=0&dname=0ss&stype=1&index=118332200000&pagenum=1),
[Daijisen](http://dic.yahoo.co.jp/dsearch?enc=UTF-8&p=%E5%89%8D&dtype=0&dname=0na&stype=1)

In itinin-mae, the sense is "a person of ability and skills", hence an adult.
This is the second meaning given above. Depending on the context, the first
meaning is also possible: a serving (such as food) suitable for one person.

