Definitions:
tending or designed to stick to things on contact

(of the weather) hot and humid; muggy

involving problems; difficult or awkward

(of a website or its content) attracting a long visit or repeat visits from users

a piece of paper with an adhesive strip on one side, used for leaving messages or reminders.

(in an online forum) a thread containing important information that is set to remain at the top of the other threads regardless of when it was last updated