Hypertext Webster Gateway: "extrusive"
From Webster's Revised Unabridged Dictionary (1913) (web1913)
Extrusive \Ex*tru"sive\, a. [See {Extrude}.] (Geol.)
Forced out at the surface; as, extrusive rocks; -- contrasted
with {intrusive}.
From WordNet (r) 1.7 (wn)
extrusive
adj : (geology) of rock material; forced out while molten through
cracks in the earth's surface [ant: {intrusive}]
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