If you observe something such as a law or custom, you obey it or follow it. Imposing speed restrictions is easy, but forcing motorists to observe them is trickier The army was observing a ceasefire
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 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