http://en.wikipedia.org/wiki/Lamb
This is a glossary of terms that relate to sheep and domestic sheep. Note that some terms have localised meanings, and may be used only in one geographical region, or may mean slightly different things in different areas.
Cryptorchid � a male sheep with no descended testicles, with them both being retained internally.
Ewe � a female sheep, capable of producing lambs.
Hoggett (or Hoggatt) � a sheep which by virtue of its age and development is no longer a lamb, but not yet mutton. esp. in relation to meat breeds.
Lamb � a young sheep, generally unweaned. In many Eastern countries, there is a less strict definition of lamb which may include older hoggetts. Also used to refer specifically to the meat of such a sheep.
Monorchid � a male sheep that has only one descended testicle, with the other being retained internally. They are less fertile but have an increased production of lean meat due to the presence of testosterone.
Mutton � an older female sheep to be used for meat. Also used to refer specifically to the meat of such a sheep. May refer to goat meat in eastern countries. Derived from the French word Mouton (sheep).
Ram (also called a tup) � an uncastrated male sheep.
Riggwelter � a sheep that has fallen onto its back and (usually because of the weight of its fleece) is unable to get back up.
Old-season lamb � a lamb a year old or more.
Ovine � member of the genus Ovis.
Slink � a very young lamb.
Sucker � an unweaned lamb.
Teg � a sheep in its second year.
Wether � a castrated male sheep.