underestimate

nouns

an estimation that is too low; an estimate that is less than the true or actual value

assign too low a value to

"Don't underestimate the value of this heirloom-you may sell it at a good price"

is derived from

antonym

make a deliberately low estimate

"The construction company wanted the contract badly and lowballed"

lowball, underestimate

is derived from

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"

underestimate, underrate

is derived from

antonym