Definition of commerce:
the exchange or buying and selling of commodities; esp. the exchange of merchandise, on a large scale, between different places or communities; extended trade or traffic; social intercourse; the dealings of one person or class in society with another; familiarity
"Fifteen years of thought, observation, and commerce with the world had made him [Bunyan] wiser." -Macaulay.
to carry on trade; to traffic. [Obs.]; to hold intercourse; to commune
"beware you commerce not with bankrupts. -B. Jonson."