If you want to point your domain to a third-party host or simply maintain the domain without hosting, you can use the default nameservers provided by your domain registrar. The appropriate default nameservers for common registrars are listed below:
Namecheap
If your domain is registered with Namecheap, use the following nameservers:
dns1.registrar-servers.com
dns2.registrar-servers.com
Liquid
If your domain is registered with Liquid, use:
ns1.liqu.id
ns2.liqu.id
PDR (Public Domain Registry)
If your domain is registered with PDR, use:
domainloin.mars.orderbox-dns.com
domainloin.earth.orderbox-dns.com
domainloin.venus.orderbox-dns.com
domainloin.mercury.orderbox-dns.com
Cosmotown
If your domain is registered with Cosmotown, use:
ns1.cosmotown.com
ns2.cosmotown.com
ns3.cosmotown.com
ns4.cosmotown.com
Global Domain Group LLC
If your domain is registered with Global Domain Group LLC, use:
ns1.globaldomaingroup.com
ns2.globaldomaingroup.com
To verify your domain registrar, you can use this tool:
https://whois.com/