Guesstimate
is an informal English portmanteau of the words guess and estimate, first used by American statisticians in 1934 or 1935.
It is defined as an estimate made without using adequate or complete information, or, more strongly, as an estimate arrived at by guesswork or conjecture.
Like the word estimate, guesstimate may be used as a verb or a noun (with the same change in pronunciation).
A guesstimate may be a first rough approximation pending a more accurate estimate, or it may be an educated guess at something for which no better information will become available.
