Ha ha they said 'dump'

This from the OECD's Transfer Pricing Guidelines
for Multinational Enterprise and Tax Administrations:

"For example, such enterprises may be subject to conflicting governmental

pressures (in the domestic as well as foreign country) relating to customs

valuations, anti-dumping duties, and exchange or price controls. "

What does 'anti-dumping' mean? And what implications does it have for a blumpkin?