an estimation that is too low; an estimate that is less than the true or actual value
make too low an estimate of; "he underestimated the work that went into the renovation"; "Don't underestimate the danger of such a raft trip on this river"
an agreement between parties (usually arrived at after discussion) fixing obligations of each; "he made a bargain with the devil"; "he rose to prominence through a series of shady deals"
an advantageous purchase; "she got a bargain at the auction"; "the stock was a real buy at that price"