overestimate vs overreckoning

overestimate and overreckoning both are nouns.

Word	Noun	Adjective	Verb	Adverb
overestimate	Yes	No	Yes	No
overreckoning	Yes	No	No	No

As nouns, overestimate and overreckoning are synonyms defined as:

overestimate and overreckoning: a calculation that results in an estimate that is too high

Other synonyms of overestimate include overestimation, overrating.

overestimate (noun)	overreckoning (noun)
a calculation that results in an estimate that is too high	a calculation that results in an estimate that is too high
an appraisal that is too high

overestimate (verb)	overreckoning (verb)
make too high an estimate of
assign too high a value to