(1) Electronic circuitry that is designed to perform a specific task.  See 
hard coded.
(2) Devices that are closely or tightly coupled.  For example, a hardwired terminal is directly connected to a computer without going through a switched network.  For example, monitors are hardwired to the computer.
(3) Fixed placement; for example, text and graphics that never change their location on a page.  A "hardwired banner" is a banner ad that never changes.
(4) A device connected to the network via cable.  See 
Ethernet.
(5) For a similar sounding term, see 
hotwired.