"Unrestricted immigration" refers to a situation where there are no limitations or restrictions on people moving and settling in a particular country. It means that anyone, without any specific requirements or regulations, can freely enter and live in that country.
Full definition
Many traditional Labour supporters voted Leave to end the ridiculous policy
of unrestricted immigration from poor Eastern European countries.
Switzerland currently has access to the European single market as a result of a series of bilateral agreements with the EU which
include unrestricted immigration for EU nationals which it has recently attempted to renegotiate.
Yes, in theory, in a libertarian state,
unrestricted immigration is good.
In practice, in 2013 USA,
unrestricted immigration is a net net minus to overall freedom, because it detracts from the freedom of people who would be forced to pay for those immigrants.
On immigration Bower demonstrates that beyond the chaos of the Home Office Blair believed that
unrestricted immigration was good for the country.