(~s, observing, ~d)
Frequency: The word is one of the 3000 most common words in English.
1.
If you ~ a person or thing, you watch them carefully, especially in order to learn something about them.
Stern also studies and ~s the behaviour of babies...
Our sniper teams ~d them manning an anti-aircraft gun.
VERB: V n, V n -ing, also V, V n inf
2.
If you ~ someone or something, you see or notice them. (FORMAL)
In 1664 Hooke ~d a reddish spot on the surface of the planet.
VERB: V n
3.
If you ~ that something is the case, you make a remark or comment about it, especially when it is something you have noticed and thought about a lot. (FORMAL)
We ~ that the first calls for radical transformation did not begin until the period of the industrial revolution...
‘He is a fine young man,’ ~d Stephen.
VERB: V that, V with quote
4.
If you ~ something such as a law or custom, you obey it or follow it.
Imposing speed restrictions is easy, but forcing motorists to ~ them is trickier...
The army was observing a ceasefire...
VERB: V n, V n