lissener said,
I kind of thought the point was that it doesn’t mean exactly the same thing as either of the words it is replacing. Guesses are not reliable enough, but an estimate can be too strong. Tell someone that you guess something is true and they’ll get all upset about how you have no idea what you’re talking about. On the other hand, tell them that you have estimated something and a lot of people will try to hold you to it. Guesstimate is for the gray area in between the two - an attempt at an accurate assessment combined with a frank admission of uncertainty.
Still, I avoid words like guesstimate because it usually wastes time as the conversation is diverted into debates about whether neologisms are acceptable. Even so, I am often struggle for words to get my meaning across.
Customer: What is price on Accessory B with the special on Product A?
Me: Well, since the 10% discount doesn’t apply to accessories, I guess your price would be about $55.
Customer: You quess?! Find me someone who knows what they’re talking about.
Customer: What is price on Accessory B with the special on Product A?
Me: Well, the 10% discount doesn’t apply to the accessory, so I estimate the total price to be $54.95.
(Interlude: after applying sales tax in a slightly different way than I had used in my estimate, the total is found to be $55.02.)
Customer: No, I can’t pay that. You quoted me a different price. Find me someone who knows what they’re talking about.
Hmm.
Anyway, I got into a discussion of homogenous vs. homogeneous the other day. I had thought homogenous meant only “having similar structure, due to descent from a common evolutionary stock”, but it apparently also means “homogeneous”. Funny. Anyway, I think this is due to the term “homogenized” being applied to milk - it means “made homogeneous” but it is pronounced more like “homogenous”, so the latter term was expropriated. Just my theory.