1. observe - Noun
2. observe - Verb
To take notice of by appropriate conduct; to conform one's action or practice to; to keep; to heed; to obey; to comply with; as, to observe rules or commands; to observe civility.
To be on the watch respecting; to pay attention to; to notice with care; to see; to perceive; to discover; as, to observe an eclipse; to observe the color or fashion of a dress; to observe the movements of an army.
To express as what has been noticed; to utter as a remark; to say in a casual or incidental way; to remark.
To take notice; to give attention to what one sees or hears; to attend.
To make a remark; to comment; -- generally with on or upon.
Source: Webster's dictionaryWhen I am at Rome I fast as the Romans do; when I am at Milan I do not fast. So likewise you, whatever church you come to, observe the custom of the place, if you would neither give offence to others, nor take offence from them. Ambrose
To acquire knowledge, one must study; but to acquire wisdom, one must observe. Marilyn vos Savant
There are people who observe the rules of honor as one observes the stars, from a great distance. Victor Hugo
Behave like the chameleon: look forward and observe behind. Madagascan Proverb
Before killing the chicken carefully observe the character of your guest. Mandingo Proverb
Observe your enemies, for they first find your faults. Greek Proverb