Adult

At twenty years of age and upwards, God considered a man an adult

Numbers 14:26 And the LORD spake unto Moses and unto Aaron, saying,
27 How long shall I bear with this evil congregation, which murmur against me? I have heard the murmurings of the children of Israel, which they murmur against me.
28 Say unto them, As truly as I live, saith the LORD, as ye have spoken in mine ears, so will I do to you:
29 Your carcases shall fall in this wilderness; and all that were numbered of you, according to your whole number, from twenty years old and upward which have murmured against me.
30 Doubtless ye shall not come into the land, concerning which I sware to make you dwell therein, save Caleb the son of Jephunneh, and Joshua the son of Nun.
31 But your little ones, which ye said should be a prey, them will I bring in, and they shall know the land which ye have despised.
32 But as for you, your carcases, they shall fall in this wilderness.
33 And your children shall wander in the wilderness forty years, and bear your whoredoms, until your carcases be wasted in the wilderness.