# armor bearer

The armor bearer carried the large shield of his commanding officer and other weapons. He protected the commanding officer during a battle.

# these uncircumcised

"these men who have not been circumcised" or "these non-Israelite men" 

# would not

"would not do what Saul had told him to do"

# took his own sword and fell on it

"killed himself with his own sword". Saul receives his punishment from God; for his disobedience and resisting God's will.