ter·rar·i·um (tə-râr'ē-əm) n.
pl.ter·rar·i·ums or ter·rar·i·a (-ē-ə) A small enclosure or closed container in which selected living plants and sometimes small land animals, such as turtles and lizards, are kept and observed.
[New Latin terrārium : Latin terra, earth; see terrene + -arium.]