/ob'zerr vay"sheuhn/ , n.
1. an act or instance of noticing or perceiving.
2. an act or instance of regarding attentively or watching.
3. the faculty or habit of observing or noticing.
4. notice: to escape a person's observation.
5. an act or instance of viewing or noting a fact or occurrence for some scientific or other special purpose: the observation of blood pressure under stress.
6. the information or record secured by such an act.
7. something that is learned in the course of observing things: My observation is that such clouds mean a storm.
8. a remark, comment, or statement based on what one has noticed or observed.
9. the condition of being observed.
10. Navig.
a. the measurement of the altitude or azimuth of a heavenly body for navigational purposes.
b. the information obtained by such a measurement.
11. Obs. observance, as of the law.
[ 1350-1400; ME observation- (s. of observatio ), equiv. to observat ( us ) (ptp. of observare to OBSERVE) + -ion- -ION ]
Syn. 3. attention. 8. pronouncement, opinion. See remark .