1) An artificial boundary, erected to contain or protect. May be used as a verb or a noun, eg to plant a hedge or to hedge one's bets.

• In gardening and agriculture, a hedge or hedgerow is a boundary formed by growing plants so that their limbs intertwine. This is the original meaning of the word. It may also refer to the Osage-orange tree which is a commonly called a hedge tree.
• In gambling and finance, a hedge is a bet or investment taken to reduce loss if another bet or investment turns out unfavourably.
• In linguistics, hedges are intentionally non-comittal or ambiguous sentence fragments, such as "sort of", "kind of", "like".

2) As a prefix it "notes something mean, vile, of the lowest class" ^* att. 1530, in the sense of plying one's trade under a hedge eg a hedge-priest or hedge-lawyer.

Hedge