Definition of "guesstimate" in English

noun

1. (informal) An estimate that is hardly any better than a guess, often because it is based on insufficient or unreliable data.

   • Near-synonym: educated guess
   • I'm not sure how many people were at the festival. My best guesstimate is 50,000.

verb

1. (intransitive) To make a guesstimate.

2. (transitive) To make a guesstimate of a specific quantity.