A portmanteau of "j" and "imaginary" for the imaginary component of a complex number. This means the same thing as Imaginary Number, and typically this number would have an italicized i after it. In electrical engineering, the letter "i" has other and more apparent meanings, so to avoid confusion we pick the next letter, j.
Compare imaginary with jimaginary number Sheldon would use 1 + 2i.
Howard would use 1 + 2j.
noun 1. a strengthened version of fag
2. fag on various ircservers.
1.
<personA> omg that guy is suc ha fag
<personB> more than a fag.. he's a JAMFAG
2.
12:02 <Jamflange`cold> sif correct you spelling ronny
12:02 <Jamflange`cold> your only gonna fuck up again next sentencer
12:02 <Jamflange`cold> sentence*
Acronym for 'Just Another Mother-Fucking Arsehole Geo', in common use amongst exploration drillers in particular in the goldfields of Australia to refer to geologists.