To gain access through hacking. It can also describe a situation where you are able to log into another person's email/computer/username/etc. simply because they left their password on the 'remember always' setting
I got haccess into the CIA national database and found that military-grade toilet seats really do cost upwards of $20,000
My brother left his computer on, so I got haccess into his facebook and made all of his info 'i like dick'.
To gain access, or acquire without permission.
I 'haccessed' my neighbor's WiFi.