Tom is an increasingly popular Hebrew name. Actually it is not Tom, short for Thomas, but Tom, a variant of the Hebrew word tam. This enables people to give their children an English-sounding name (which is considered cool in certain Israeli circles) that is nonetheless still Hebrew.
Tam translates as whole, or unblemished. As a character description it means innocent, sincere, or simple. In the Bible, the young Jacob is an ish tam, a simple man, who sat in tents (Genesis 25:27), contrasting with his brother Esau, a cunning hunter. Noah is described as tzadik vtamim, righteous and upright, though only in his generation (Genesis 6:9).
The Torah urges us to be tamim with God, (Deuteronomy 18:13), which in context means not trying to second guess Gods plans by consulting astrologers and fortune tellers.
The most famous tam is the simple child in the Hagadah, who only grasps what is going on sufficiently to ask Whats this? Tam here is not wholly complimentary.
Tam can also be applied to animals. A shor tam is an ox of a previously placid disposition that does not have a track record of hurting people. The Mishnah (Baba Kama 1:4 ) contrasts this with a shor muad, which is prone to do damage. If the shor tam suddenly goes crazy and gores somebody, then its owner is fined more leniently than if it was a shor muad, which the owner should have known to keep in check.