low speed
adj.— «“Roger that,” said Young, clutching his soggy worksheet. “You guys are high speed.” High speed is a military term of endearment. Low speed, conversely, denotes anything uncool, such as Gussman’s older-edition helmet, which kept swimming around on his head and was due to be replaced. Gussman with the grappling hook? High speed.» —“An old soldier in a new war” by Jon Rutter LancasterOnline.com (Pennsylvania) May 18, 20008. (source: Double-Tongued Dictionary)
Further reading
In 1968, students at Cheyenne High School in Cheyenne, Wyoming, compiled a collection of their own slang, including the word Clyde, used to refer to one’s head, as in Use your Clyde! This is part of a complete episode.
Related
We use the term Milky Way for that glowing arc across the sky. But how people picture it varies from culture to culture. In Sweden, that starry band goes by a name that means “Winter Street,” and in Hawaii, a term for the Milky Way...