what did children in the 1600 call adults?

Question

I have been looking for an answer to this simple (and dumb) question, in any case this so called "adult" is not represented as this child's parent. Just one he knows the name of.

Answer 1

The sense of "full-grown human being" of the word adult developed in the mid-1650s from its usage as an adjective meaning *mature" which arose in the early 1600s (see https://www.etymonline.com/word/adult). Before this, it seems that there was no gender-neutral term for a fully-grown human being - an adult was either referred to as either a "man" or a "woman" to indicate their maturity (https://www.etymonline.com/word/man#etymonline_v_6766). For example, consider the words "manhood" and "womanhood", which convey maturity/adulthood in contrast to words such as "boyhood" and "girlhood", which convey immaturity/childhood. Also consider phrases such as "you've grown into a fine young man/woman" which indicate that the listener has grown up to be a productive member of society.

I hope that helps! Did you read this in a book somewhere?