In modern Swedish, "Karl" means "Man".

"En riktig karl!"

"A real man!"

The Karls were not nobility (Jarl) nor slaves (Träl). But free men.

Such as farmers and warriors.

Swedish (language) - svenska

Swedish (adjective, nationality) - svensk

Swedish fish is made by the Swedish candy producer Malaco.

If a man was not born into nobility, and the Monarch liked him, the Monarchy could grant him nobility status. Or, a man could buy the right to be let into nobility. Otherwise, a single man could gain the right by marrying into nobility.

Noble is the adjective related to nobility. Adjectives to describe nobility include landed, aristocratic, and gentle.