Real Dictionary

lowball in American English
of or having to do with prices, estimates, fares, etc. that are kept very low, esp. so as to take away sales from competitors
to give an understated price, estimate, etc. to (someone), esp. without intending to honor it
adjective: engaged in or characteristic of lowballing
intransitive verb: to engage in lowballing
noun: a game of draw poker in which the player having the lowest-ranking hand wins the pot
transitive verb: to deliberately estimate a lower price for (a service or merchandise) than one intends to charge

lowball in British English
noun: a game of poker in which the player with the lowest hand wins
verb: to make a very low estimate or offer for (a service, product, company, etc)