Eruptive

adv. tending to burst forth suddenly; causing a skin rash (Pathology); characterized by a skin rash (Pathology)

Adjective
1. igneous rock produced by eruption and solidified on or near the earth's surface; rhyolite or andesite or basalt; "volcanic rock includes the volcanic glass obsidian"
(synonym) volcanic
(similar) extrusive
2. of igneous rock that has solidified beneath the earth's surface; granite or diorite or gabbro
(synonym) irruptive, plutonic
(similar) intrusive
3. erupting or tending to erupt; "a geyser is an intermittently eruptive hot spring"
(similar) active

adj. eruptive, tending to burst forth suddenly, causing a skin rash (Pathology); eruptional, of or pertaining to an eruption

adj. eruptive, tending to burst forth suddenly; causing a skin rash (Pathology)

(n.)
An eruptive rock.
  

(a.)
Produced by eruption; as, eruptive rocks, such as the igneous or volcanic.
  

(a.)
Breaking out or bursting forth.
  

(a.)
Attended with eruption or efflorescence, or producing it; as, an eruptive fever.