a half-assed job at estimating.

someone who is sexy beyond mean

An educated guess. A guesstimation is a guess, but at the same time an estimation.

a mix between guessing and estimating.

guess + estimate = guesstimate

its that simple.

1. Originally used by morons who like to make up words, guesstimate is a combination of two words that don't mean quite the same thing; A combination of the words Guess and Estimate that has adopted the meaning of the word guess.

2. To Guess; To draw a conclusion with little or no reason to believe so.

The way stupid people say "estimate". They either think they're being cute or clever, or else that it's an actual word. Since it's not any of these, science has yet to offer an explanation for people who consider use of this word acceptable.

an aproximation; an annoying phrase likely originating from high school science teachers.