Definition of "Observe" :

verb: stick to correctly or closely

verb: make mention of

"She observed that his presentation took up too much time."

verb: observe with care or pay close attention to

verb: discover or determine the existence, presence, or fact of

verb: watch attentively

"Please observe the reaction of these two chemicals."

verb: follow with the eyes or the mind

verb: show respect towards

verb: behave as expected during of holidays or rites

"Observe Yom Kippur."

verb: conform one's action or practice to