S: (n) monitoring (the act of observing something (and sometimes keeping a record of it)) "the monitoring of enemy communications plays an important role in war times"
S: (n) sighting (the act of observing) "several sightings of enemy troops were reported"
W: (v) observe [Related to: observation] (follow with the eyes or the mind) "Keep an eye on the baby, please!"; "The world is watching Sarajevo"; "She followed the men with the binoculars"
W: (v) observe [Related to: observation] (observe with care or pay close attention to) "Take note of this chemical reaction"
W: (v) observe [Related to: observation] (stick to correctly or closely) "The pianist kept time with the metronome"; "keep count"; "I cannot keep track of all my employees"
W: (v) watch [Related to: watching] (observe with attention) "They watched as the murderer was executed"