means A spout is a tube, lip, or nozzle through which liquid is poured or forced out, or the act of gushing forth — and figuratively, to talk on and on with the same forceful flow.

from From Middle English 'spouten,' to flow or gush, likely related to Middle Dutch 'spouten' and the broader Germanic family of words for spitting and spewing — a cousin of 'spit' and 'spew,' all of them echoing the wet, percussive sound of liquid being expelled under pressure. The figurative sense of a person 'spouting' words came later, the mouth recast as just another nozzle.