Sam

Sam is a familiar form of Samuel and Samantha, and it is also used as an independent given name. Through Samuel it connects with a Hebrew biblical tradition, though the name's precise ancient interpretation is debated. That history should not automatically be assigned to every Sam, since some families start from a different longer name.

Sammy is a familiar extended nickname, while Sam itself is already a complete single syllable. It can preserve an honor for a Samuel or Samantha without repeating the full name. For families choosing Sam directly, the simplicity is part of the name's form rather than evidence that a longer official version is missing.