A word a young person might call someone more mature than them when the older individual has opposing ideas and the younger person doesn't know how to defend their point of view.
30 YEAR OLD MAN: You can't expect a promotion and raise for just showing up. If you do more, you will get more.
CHILD: Ok boomer.
A boomer is.......Greta tunberg
Yo Greta is such a boomer like, oh my god ur so right
A boomer is a old person, who knows nothing of the 21st century.
Boomer descripes a person who is born in the mid 20 century.
(If you came to the idea to Google the therm, when you're probably not a boomer)
"See son, this website says that I'm not a boomer"
"No mom it uses probably, so you're still a boomer"