guess: [13] In the earliest records we have of the verb guess, it is used for ‘take aim’. The modern sense ‘estimate’ did not emerge until the mid- 14th century. It seems to be of Scandinavian origin, and probably comes ultimately from the same base as produced get (Old Norse geta meant ‘guess’ as well as ‘get’, and the semantic progression hinted at by the intermediate ‘take aim’ is probably via ‘lock on to something in one’s sights’ to ‘fix on a particular figure’ – by implication, without exact calculation). Guesstimate, a blend of guess and estimate, is a US coinage of the 1930s. => get[guess etymology, guess origin, 英语词源]