out- /aʊt/ BrE AmE prefix
1 . used to form nouns and adjectives from verbs that are followed by ‘out’:
an outbreak of flu (=from ‘break out’)
outspoken comments (=from ‘speak out’)
2 . [in nouns and adjectives] outside or beyond something:
an outbuilding (=small building away from the main building)
outlying areas (=far from the centre)
3 . [in verbs] being or becoming bigger, further, greater etc than someone or something else:
He’s outgrown his clothes (=become too big for them) .
She outlived her brother (=he died before her) .
4 . [in verbs] doing better than someone, so that you defeat them:
I can out-argue you any day.
She outran him.