In 1st Samuel 25, we read about Abigail's first husband, who is
named Nabal. Near the end of the story, she pleads with David to
save his life: My lord should not pay attention to this wicked
man Nabal. He simply lives up to his name! His name means
‘fool,’ and he is indeed foolish! But I, your servant, did not
see the servants my lord sent.—1st Samuel 25:25 (NET) So there
seem to be three possibilities: Nabal's parents thought it would
be a good idea to name their son Fool. (This is perhaps not as
unlikely as it seems.) Nabal didn't mean fool when it was given
as a name. (Perhaps the meaning arose from this story or perhaps
it came from another language or dialect.) His name was
unrecorded initially and supplied by a later editor. How should
we read this unusual name?