1) the study of ancient things, especially the buried remains of prehistoric times (archaeology)
2) (a part or mark of) a prehistoric animal or plant once buried in earth, now hardened like rock (fossil)
having a lot of work to do
engaged, at work
(of glances, threats etc) hidden; disguised
clandestine, underhanded
(of people, animals, plants) no longer living
no longer alive
going a long way down from the top
extending very far, usually down
of forget
out of one's mind
of hide
unseen, secret
to defeat, be too strong for, (a person, habit etc); to make (a person) weak, unhappy or ill
overwhelmed; visibly moved
underground
hidden, underground
that has sunk; (made) lower than the rest of the surface
depressed, hollowed; submerged
beyond what is first seen or said
secret; pertaining to a hidden goal
under the surface of the ground; acting secretly (especially of a movement for resisting the enemy); in, to, a secret place, situation
below the surface