Close Combat Defense

From SFWiki

This skill aids in the characters defense (dodge) versus close combat weapons, including non-ranged innate weapons of monsters and people.

Higher ranks in this skill mean that the character is less likely to be struck by a foe's attack with close combat weaponry. It does not provide any bonus versus ranged weapons of any kind.

This is generally a poor choice for starting characters, as the vagaries of defense do not show value until later in the game.