From Wiktionary
deep is on the Basic English 850 List.
decision - deep - degree
deep is one of the 1000 most common headwords.
decision - deep - definite






A deep hole
  1. A hole or body of water is deep if it goes down a long way.
    Do not dive into this swimming pool because it is not deep enough.
    Some oil wells must be drilled deeper than others to reach the oil.
  2. Something is deep if it is far below or inside.
    The Earth's iron core is deep beneath its crust.
    The Japanese style of poetry called haiku is simple on the surface, but it should also have a deeper emotional meaning.
  3. A deep voice has low-pitched tones.
    In opera, the bass singer has the deepest voice.
  4. With actions that make something smaller, we say deep to mean they make them much smaller.
    This furniture store offers deep discounts on beds.
    The new budget makes deep spending cuts in education.
  5. An idea is called deep if it has an important meaning that is not easy to see.
    A: 'I think you like heavy metal music because your parents don't approve of it.' B:'Wow, that's deep!'