The word used to reply to a question or sentence you either did not understand, misheard, were confused by or you did not hear.
Similar to nes.
Dave: You done that homework?
Jonzy: Huh?, sorry I was looking at the seagullsoutside.
Dave: Huh?
Jonzy: Yeah the seagulls are going fucking crazy out there!
Can be used to denote that the previous statement was counterintuitive or surprising, requiring a pause to absorb its significance.
<Joe> Yeah, so a tomato is a fruit, not a vegetable.
<Bob> Huh.
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<Eazy-E> I went to the hospital with a really bad cough, and the doctor diagnosed me with AIDS.
<Jerry> Huh.