“That ‘70s Show” was known for using pop culture references and slang from the ‘70s that made viewers who grew up in the era feel nostalgic. However, fans from younger generations or those unaware of '70s slang have had difficulty understanding certain phrases from the show.
A recent Reddit thread asked what the characters on “That ‘70s Show” meant when they referred to their classmates as “heads.” Fans of the show flocked to the comments section to answer the question, and the consensus was that the term meant "pothead."
While the term "head" is accurate to the slang of the era, the writers may have also chosen that word to adhere to network television guidelines. Fox prohibited the series from showing its young characters smoking marijuana, but every fan of the show knew what was really going on in those “circle” scenes.