a maanyi, a magezi.

a- (ka/bu) small tree; small stick, okukola ekintu n'odda ne mu kati, to do something excessively/to an extreme degree; to do something wonderfully/efficiently. Yayimba n'adda ne mu kati. He sang wonderfully. Twalya ne lukubyako kati. We ate excessively and still had plenty left over. cf. omuti.

i.e., one who finishes quickly and hustles others, an efficient but intolerable person.