expression, reflexion, reflection, manifestation - expression without words; "tears are an expression of grief"; "the pulse is a reflection of the heart's condition"

acting out - a (usually irritating) impulsive and uncontrollable outburst by a problem child or a neurotic adult

cry - a fit of weeping; "had a good cry"

explosion - a sudden outburst; "an explosion of laughter"; "an explosion of rage"

flare - a sudden outburst of emotion; "she felt a flare of delight"; "she could not control her flare of rage"