A number whose decimal representation ends in one or more zeroes. / A rough approximation, especially one whose decimal representation ends in one or more zeroes.

(transitive, arithmetic) To round (a number) to the greatest integer that is not greater than it, or to some other lower value, especially a whole number of hundreds, thousands, etc.

(transitive) To gather (cattle) together by riding around them. / (transitive, idiomatic) To collect or gather (something) together.

(often figuratively, travel) A trip from one destination to another and then returning to the starting location.

(US, humorous) A circular object supposedly giving its owner the ability to get done everything that would have otherwise been put off to a later date "when they got around to it".

(geometry) An angle of 360 degrees; a full circle.

simple past tense and past participle of round up

Of cattle etc.: gathered together as a group. / (mathematics) Of a real number: converted to an integer by having 0.5 added to it, and the result being rounded down.

simple past tense and past participle of round down

(mathematics) Of a real number, converted to an integer by having its fractional component removed.