Main Difference
The main difference between Tomb and Mausoleum is that the Tomb is a burial place and Mausoleum is a monument enclosing the interment space or burial chamber of a deceased person or people.
Tomb
A tomb (from Greek: τύμβος tumbos) is a repository for the remains of the dead. It is generally any structurally enclosed interment space or burial chamber, of varying sizes.
Mausoleum
A mausoleuma is an external free-standing building constructed as a monument enclosing the interment space or burial chamber of a deceased person or people. A monument without the interment is a cenotaph. A mausoleum may be considered a type of tomb, or the tomb may be considered to be within the mausoleum.
Tomb (noun)
A small building (or “vault”) for the remains of the dead, with walls, a roof, and (if it is to be used for more than one corpse) a door. It may be partly or wholly in the ground (except for its entrance) in a cemetery, or it may be inside a church proper or in its crypt. Single tombs may be permanently sealed; those for families (or other groups) have doors for access whenever needed.
Tomb (noun)
A pit in which the dead body of a human being is deposited; a grave.
Tomb (noun)
One who keeps secrets.
Tomb (verb)
To bury.
Mausoleum (noun)
A large stately tomb or a building housing such a tomb or several tombs.
Mausoleum (noun)
A gloomy, usually large room or building.
Tomb (noun)
a large vault, typically an underground one, for burying the dead.
Tomb (noun)
an enclosure for a corpse cut in the earth or in rock.
Tomb (noun)
a monument to the memory of a dead person, erected over their burial place.
Tomb (noun)
used in similes and metaphors to refer to a place or situation that is extremely cold, quiet, or dark, or that forms a confining enclosure
“the house was as quiet as a tomb”
Tomb (noun)
death
“none escape the tomb”