1.
If someone or something goes over to a different way of doing things, they change to it.
The Armed Forces could do away with conscription and ~ a volunteer system.
PHRASAL VERB: V P P n
2.
If you ~ a group or political party, you join them after previously belonging to an opposing group or party.
Only a small number of tanks and paratroops have gone over to his side.
PHRASAL VERB: V P P n