1. discover or determine the existence, presence, or fact of

Similar word(s): detect, discover, find, notice

Definition categories: perception, sight, spy

2. make mention of

- She observed that his presentation took up too much time

Similar word(s): mention, note, remark

Definition categories: communication, say, state, tell

3. observe with care or pay close attention to

Similar word(s): note

Definition categories: perception

4. watch attentively

- Please observe the reaction of these two chemicals

Definition categories: perception, watch

5. show respect towards

Similar word(s): honor, honour, respect

Definition categories: social, accept

6. behave as expected during of holidays or rites

- Observe Yom Kippur

Similar word(s): celebrate, keep

Definition categories: social

7. follow with the eyes or the mind

Similar word(s): follow, watch

Definition categories: social, check

8. stick to correctly or closely

Similar word(s): keep, maintain

Definition categories: cognition

9. conform one's action or practice to

Similar word(s): keep

Definition categories: social

Sentences with observe as a verb:

- From this vantage point we can observe the behavior of the animals in their natural habitat.

- Please observe all posted speed limits.

- The senator observed that the bill would be detrimental to his constituents.