What does OBSERVE mean?

verb

1. discover or determine the existence, presence, or fact of“She detected high levels of lead in her drinking water”
2. make mention of“She observed that his presentation took up too much time”
3. observe with care or pay close attention to“Take note of this chemical reaction”
4. watch attentively“Please observe the reaction of these two chemicals”
5. show respect towards“honor your parents!”
6. behave as expected during of holidays or rites“Keep the commandments”
7. follow with the eyes or the mind“Keep an eye on the baby, please!”
8. stick to correctly or closely“The pianist kept time with the metronome”