Many name books / websites list the meaning of CALEB as "Dog". However, a simple look in a Hebrew / English dctionary one will see that "dog" in Hebrew is CELEB, not CALEB. **Note** the first vowel is different.
CALEB is actually a compound word in Hebrew - something that is quite common in ancient Hebrew. Col (Cuf + Lamed) = all or whole. Lev (Lamed + Vet) = heart. Therefore, CALEB (or COLEV as pronounced in Hebrew) actually means "whole hearted".
Faithful could be another translation. However, if you read in the Hebrew Bible the exploits of CALEB (as in one of the twelve spies who went into Caanan Numbers 13:6 & 13:30), one will see that he wasn't simply faithful, but that he served the God of ISRAEL with his whole heart. IE: He was the first to speak up and say, "let's go and conquer this land," (paraphrased). It wasn't JOSHUA (the leader of the 12 spies), but CALEB who was encouraging Israel to follow God inspite of the opposition from the other 10 spies.
Therefore, the ancient meaning of CALEB is: "whole hearted".