A piece of slang that rapidly enters a collective global or regional consciousness and is overused by speakers without their intent ... THEY CAN'T HELP IT.
"Stop saying, 'Epic.' It's played out."
"I know, but I can't help it. It's totally a slangworm."
1975 - Groovy; 1985 - Rad; 1995 - Sick; 2005 - Hella; 2010 - Epic