Open English Wordnet
Nouns
(n)estimate, estimation, approximation, ideaan approximate calculation of quantity or degree or worth“an estimate of what it would cost”, “a rough idea how long it would take”
(n)approximationan imprecise or incomplete account“newspapers gave only an approximation of the actual events”
(n)approximation, bringing close togetherthe act of bringing near or bringing together especially the cut edges of tissue