observation

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The act or faculty of observing.
2. n. The fact of being observed.
3. n. The act of noting and recording something, such as a phenomenon, with instruments.
4. n. The result or record of such notation: a meteorological observation.
5. n. A comment or remark. See Synonyms at comment.
6. n. An inference or a judgment that is acquired from or based on observing.

Century Dictionary and Cyclopedia

1. n. The act or fact of observing, and noting or fixing in the mind; a seeing and noting; notice: as, a fact that does not come under one's observation.
2. n. The habit or power of observing and noting: as, a man of great observation.
3. n. An act of scientific observing; an accurate remarking (often with measurement) of a fact directly presented to the senses, together with the conditions under which it is presented: as, a meridian observation, made by a navigator, in which he measures the sun's altitude when on the meridian for the purpose of calculating the latitude; the meteorological observations made by the Signal Service Bureau. In those sciences which describe and explain provinces of the universe as it exists, such as astronomy and systematic biology, observations are, for the most part, made under circumstances or conditions which may be selected, but cannot be produced at will. But in those sciences which analyze the behavior of substances under various conditions it is customary first to place the object to be examined under artificially produced conditions, and then to make an observation upon it. This whole performance, of which the observation is a part, is called an experiment. Formerly sciences were divided into sciences of experiment and sciences of observation, meaning observation without experiment. But now experiments are made in all sciences. It is only occasionally that the word observation has been used to imply the absence of experimentation.
4. n. The result of such a scientific practice; the information gained by observing: as, to tabulate observations.
5. n. Knowledge; experience.
6. n. A remark, especially a remark based or professing to be based on what has been observed; an opinion expressed.
7. n. The fact of being seen or noticed; notice; remark: as, to escape observation; anxious to avoid observation.
8. n. Observance; careful attention to rule, custom, or precept, and performance of whatever is prescribed or required.
9. n. A rite; a ceremony; an observance.
10. n. Synonyms Observance, Observation. See observance.
11. n. Experiment, etc. See experience.
12. n. Note, Comment, etc. (see remark, n.), annotation.

Wiktionary

1. n. The act of observing, and the fact of being observed.
2. n. The act of noting and recording some event; or the record of such noting.
3. n. A remark or comment.
4. n. A judgement based on observing.

GNU Webster's 1913

1. n. The act or the faculty of observing or taking notice; the act of seeing, or of fixing the mind upon, anything.
2. n. The result of an act, or of acts, of observing; view; reflection; conclusion; judgment.
3. n. An expression of an opinion or judgment upon what one has observed; a remark.
4. n. Performance of what is prescribed; adherence in practice; observance.
5. n. The act of recognizing and noting some fact or occurrence in nature, as an aurora, a corona, or the structure of an animal.
6. n. Specifically, the act of measuring, with suitable instruments, some magnitude, as the time of an occultation, with a clock; the right ascension of a star, with a transit instrument and clock; the sun's altitude, or the distance of the moon from a star, with a sextant; the temperature, with a thermometer, etc.
7. n. The information so acquired.

WordNet 3.0

1. n. the act of observing; taking a patient look
2. n. the act of noticing or paying attention
3. n. facts learned by observing
4. n. the act of making and recording a measurement
5. n. a remark expressing careful consideration