Caleb is a Hebrew masculine given name. The Hebrew spelling of the name Caleb – כלב – is identical with the spelling of the word dog – "kelev". The composing of the Bible antedates by thousands of years the introduction of the Niqqud system of diacritical signs which modern Hebrew uses to represent vowels. Thus, it is difficult to ascertain how the name was originally pronounced. Many name books and websites list the meaning of Caleb as "Dog". Many Biblical characters bore animal names, including names which in the sensibilities of later times would be considered insulting, such as the woman prophet Hulda, whose name means "weasel". In some traditions, Caleb's being a "dog" symbolizes his devotion to God.
An alternate Hebrew meaning offered for Caleb is "faithful, devotion, whole hearted, bold, brave". This is on the basis of its being actually a compound word, a phenomenon quite common in ancient Hebrew. Col (כל, Kaf + Lamed) = "all" or "whole"; Lev (לב, Lamed + Bet) means "heart". Therefore, Caleb (or Calev as pronounced in Hebrew) would actually mean "whole hearted". This might be due to the Biblical Caleb, a companion of Moses and Joshua, being noted for his astute powers of observation and fearlessness in the face of overwhelming odds.
The early Medieval King Kaleb of Axum was the most well-known monarch of this kingdom (in modern Ethiopia and Eritrea). The name Caleb was popular among the English Puritans, and was introduced by them to America.