the period of time that it takes for a planet (as, e.g., Earth or Mars) to make a complete revolution around the sun; "a Martian year takes 687 of our days"
a period of time containing 365 (or 366) days; "she is 4 years old"; "in the year 1920"
a period of time occupying a regular part of a calendar year that is used for some particular activity; "a school year"
concise and full of meaning; "welcomed her pithy comments"; "the peculiarly sardonic and sententious style in which Don Luis composed his epigrams"- Hervey Allen
a period of indeterminate length (usually short) marked by some action or condition; "he was here for a little while"; "I need to rest for a piece"; "a spell of good weather"; "a patch of bad weather"
an estimation that is too low; an estimate that is less than the true or actual value
make too low an estimate of; "he underestimated the work that went into the renovation"; "Don't underestimate the danger of such a raft trip on this river"