Verb

(head)

(detect)

We detected the submarine long before it observed us.

Verb

(observ)

(lb) To notice or view, especially carefully or with attention to detail.

:

*1892 , (Arthur Conan Doyle),

*:“One horse?” interjected Holmes. ¶ “Yes, only one.” ¶ “Did you observe the colour?”

*{{quote-magazine, date=2013-03, author=Frank Fish, George Lauder

, volume=101, issue=2, page=114, magazine=(American Scientist) , title= Not Just Going with the Flow , passage=An extreme version of vorticity is a vortex . The vortex is a spinning, cyclonic mass of fluid, which can be observed in the rotation of water going down a drain, as well as in smoke rings, tornados and hurricanes.}}

(lb) To follow or obey the custom, practice, or rules (especially of a religion).

:

*Bible, (w)

*:Ye shall observe the feast of unleavened bread.

*{{quote-news, year=2011, date=November 10, author=Jeremy Wilson, work=Telegraph

, title= England Under 21 5 Iceland Under 21 0: match report , passage=A sell-out crowd of 10,000 then observed perfectly a period of silence before the team revealed their black armbands, complete with stitched-in poppies, for the match. After Fifa’s about-turn, it must have been a frantic few days for the England kit manufacturer. The on-field challenge was altogether more straightforward. }}

(lb) To comment on something; to make an observation.

:

*

*:Elbows almost touching they leaned at ease, idly reading the almost obliterated lines engraved there. ¶ ("I never) understood it," she observed , lightly scornful. "What occult meaning has a sun-dial for the spooney? I'm sure I don't want to read riddles in a strange gentleman's optics."