1A machine that makes tea bags; a company that makes or sells tea bags.
2US A person involved in a political protest or movement which seeks to reduce taxation or government spending, and which is associated with tea bags or tea as a symbolic or actual form of protest; specifically (in 2009 and the years immediately following) a supporter or member of the conservative Tea Party movement.
The association of tea with tax-related protests goes back to the Boston Tea Party of 1773.
3slang A person who performs or takes part in the sexual act of teabagging.
1940s; earliest use found in Tea & Coffee Trade Journal. From tea-bag + -er.