verb

• (transitive) To notice or view, especially carefully or with attention to detail.
  "From this vantage point we can observe the behavior of the animals in their natural habitat."
• (transitive) To follow or obey the custom, practice, or rules (especially of a religion).
  "Please observe all posted speed limits."
• (transitive) To take note of and celebrate (a holiday or similar occurrence), to keep; to follow (a type of time or calendar reckoning).
  "Ye shall observe the feast of unleavened bread."
• (intransitive) To comment on something; to make an observation.
  "The senator observed that the bill would be detrimental to his constituents."

noun

• (archaic) An observation (remark, comment or judgement).
  "“It sticks in my mind that he would take it very ill,” says Alan. “But the little man cried to me to run, and indeed I thought it was a good observe, and ran. The last that I saw they were all in a knot upon the beach, like folk that were not agreeing very well together.”"