From Longman Dictionary of Contemporary Englishrough something ↔ out phrasal verb British EnglishDETAIL#to draw or write something without including all the details a diagram the engineer had roughed out on his notepad → rough→ See Verb table
Examples from the Corpus
rough out• For all the rough treatment meted out to houses in institutional use, many retain remarkably fine interiors.• The roughs are weeded out until only the best remain. 