D defs.my
Entry 1 sense Webster, 1913

Calibration

/kălˌ-əb-rāsh'-ən/ · Cal·ibra·tion · IPA /ˌkæl.əˈbɹeɪ.ʃən/
01 n. The process of estimating the caliber a tube, as of a thermometer tube, in order to graduate it to a scale of degrees; also, more generally…
  1. 1.
    The process of estimating the caliber a tube, as of a thermometer tube, in order to graduate it to a scale of degrees; also, more generally, the determination of the true value of the spaces in any graduated instrument.