eruption

(noun) the sudden occurrence of a violent discharge of steam and volcanic material. Synonyms: volcanic eruption.

(noun) symptom consisting of a breaking out and becoming visible.

(noun) (of volcanos) pouring out fumes or lava (or a deposit so formed). Synonyms: eructation, extravasation.

(noun) a sudden violent spontaneous occurrence (usually of some undesirable condition). Synonyms: outbreak, irruption. Example: "The outbreak of hostilities."

(noun) a sudden very loud noise. Synonyms: bang, clap, blast, bam.

(noun) the emergence of a tooth as it breaks through the gum.