Synonyms:
- be vigilant,
- be watchful,
- bug,
- case,
- course,
- cover,
- do,
- eye,
- eyeball,
- follow,
- gaze at,
- go over,
- have a looksee,
- hold in view,
- keep in sight,
- keep in view,
- keep under observation,
- look after,
- look at,
- look on,
- look upon,
- make a reconnaissance,
- measure,
- observe,
- overpass,
- pass over,
- pass through,
- patrol,
- peep,
- perambulate,
- peregrinate,
- pererrate,
- play the spy,
- ply,
- probe,
- put under surveillance,
- range,
- range over,
- regard,
- scour,
- scour the country,
- scout,
- scout out,
- spy,
- spy out,
- spy upon,
- stake out,
- sweep,
- track,
- transit,
- travel over,
- travel through,
- traverse,
- view,
- voyage,
- watch