1. To become active and spew forth lava and rocks; said of volcanoes; SYN. belch.
2. To appear or intensify suddenly; SYN. flare up, flare, break open, burst out.
3. To emerge suddenly; SYN. come out, break through, push through.
4. To start abruptly; SYN. break out.
5. To manifest skin eruptions; SYN. break out.

Množina: eruptions

ETYM Latin eruptio, from erumpere, eruptum, to break out; e out + rumpere, to break: cf. French éruption. Related to Rupture.
1. The emergence of a tooth as it breaks through the gum.
2. (Of volcanos) Pouring out fumes or lava; SYN. eructation.

Singular of eruptions is eruption.

ETYM Cf. French éruptif.
1. Erupting or tending to erupt; SYN. erupting.
2. Igneous rock produced by eruption and solidified on or near the earth's surface; rhyolite or andesite or basalt; SYN. volcanic.

In an eruptive manner, with a tendency to break forth