Around, surrounding
Circum- comes from Latin "circum" (around, surrounding) and signals that something surrounds, encircles, or moves around something else: circumference = the measurement around a circle; circumstance = what "surrounds" or stands around a situation; circumnavigate = sail around (a continent or the globe); circumspect = looking around with care before acting; circumflex = an accent that curves around a letter (â, ê, î).