/ˌpɜːrpəˈtuːəti/

per·petu·ity

BrE /ˌpɜːpəˈtjuːəti/

NAmE /ˌpɜːrpəˈtuːəti/

[U]

in perpetuity

(formal)

for all time in the future

SYN forever

They do not own the land in perpetuity.