From The Collaborative International Dictionary of English v.0.48:
massive \mass"ive\ (m[.a]s"[i^]v), a. [F. massif.]
1. Forming, or consisting of, a large mass; compacted;
weighty; heavy; massy. "Massive armor." --Dr. H. More.
[1913 Webster]
2. (Min.) In mass; not necessarily without a crystalline
structure, but having no regular form; as, a mineral
occurs massive.
[1913 Webster]
Massive rock (Geol.), a compact crystalline rock not
distinctly schistose, as granite; also, with some authors,
an eruptive rock.
[1913 Webster]