means To say something very loudly, raising your voice to be heard, to express strong feeling, or to call out across a distance.

from From Middle English shouten, of uncertain origin — but possibly related to Old Norse skūta, 'a taunt or jeer,' and perhaps a cousin of 'scout' in its older sense of mockery. There's a tempting link to 'shoot,' as if a shout were a sound fired off, but that connection is folk-intuition rather than proven fact.