something or someone that causes trouble; a source of unhappiness; "washing dishes was a nuisance before we got a dish washer"; "a bit of a bother"; "he's not a friend, he's an infliction"
(electronics) the act of increasing voltage or power or current
addition of extra material or illustration or clarifying detail; "a few remarks added in amplification and defense"; "an elaboration of the sketch followed"
the amount of increase in signal power or voltage or current expressed as the ratio of output to input