Collocations for roam - verb

free, freely
The animals were allowed to roam free.

widely
the wild dog's instinct to roam widely

aimlessly
He'd roamed aimlessly for a few hours.

about (esp. BrE), around

allow sb/sth to, let sb/sth

about (esp. BrE), around
They're roaming around the countryside.

across
Wild camels roam across the country.

over
Her eyes roamed over him, assessing him.

through
Bears roam through the town at night.

the freedom to roam, the right to roam (esp. BrE)
Ramblers are calling for the right to roam to be made law.

roam the earth
when dinosaurs roamed the earth

Roam is used with these nouns as the subject:
dog, eye, gaze, hand, lion

Roam is used with these nouns as the object:
countryside, earth, hallway, neighbourhood, plain, sea, street