Clue: Lock web address after X linked to copyright (4-4)
Answer: KISS CURL
Explanation: Definition: Lock
 URL(abbrev. for "Uniform Resource Locator", the address of a webpage on the Internet) **placed below**(after, in a down clue) [ KISS(in written form, represented by "X") **plus**(linked to) C(abbrev. for "copyright", as in ©) ].
Defn: … of hair … sported by both sexes: