IRREPRESSIBLE
irrepressible, uncontrollable
(adjective) impossible to repress or control; “an irrepressible chatterbox”; “uncontrollable laughter”
Source: WordNet® 3.1
Etymology
Adjective
irrepressible (not generally comparable, comparative more irrepressible, superlative most irrepressible)
Not containable or controllable.
(of a person) Especially high-spirited, outspoken, or insistent.
Source: Wiktionary
Ir`re*press"i*ble, a.
Definition: Not capable of being repressed, restrained, or controlled; as,
irrepressible joy; an irrepressible conflict. W. H. Steward.
Source: Webster’s Unabridged Dictionary 1913 Edition