unite — to join, combine, or incorporate so as to form a single whole or unit.
combine — If you combine two or more things or if they combine, they exist together.
confine — To confine something to a particular place or group means to prevent it from spreading beyond that place or group.
hold — to have or keep in the hand; keep fast; grasp: She held the purse in her right hand. He held the child's hand in his.
join — to bring in contact, connect, or bring or put together: to join hands; to join pages with a staple.
keep — to hold or retain in one's possession; hold as one's own: If you like it, keep it. Keep the change.
limit — the final, utmost, or furthest boundary or point as to extent, amount, continuance, procedure, etc.: the limit of his experience; the limit of vision.
remain — to continue in the same state; continue to be as specified: to remain at peace.
restrain — to hold back from action; keep in check or under control; repress: to restrain one's temper.