nearly correct or exact

said of a term, etc: loose; inexact

(often + to) to come close, esp in quality or character

The animals are kept as far as possible in conditions approximating to their native habitat

(often + to) to average out

a reading rate approximating to ten books a year

to make a guess

to approach or be similar to (something), esp in quality or number

Surgery alters their anatomy so that it approximates that of the preferred sex

to simulate (something)

Flying conditions can be approximated in the laboratory

to guess (an amount)