The action of finding an IP address given a HostName, using DNS.
bash-2.05b$ host wlug.org.nz wlug.org.nz has address 203.97.10.50 wlug.org.nz mail is handled (pri=10) by smtp.wlug.org.nz
A ForwardLookup tends to use A records in DNS, though may also use any combination of CNAME?/MX? depending on what you're looking for.
Contrast ReverseLookup.
4 pages link to ForwardLookup: