'Trobas' is a phonetic term which one would hear regularly in Greece, or in any place with a healthy Greek population! Troba means 'pump' and 'trobas' therefore means 'Pumper' - in the sense of wanker. This word is interchangeable with the common Greek word Malaka which shares the same meaning. Trobas does not share the universality of 'Malaka' and therefore only experienced speakers of the language tend to use this word. Like 'Malaka' ,trobas may be used to express greeting (in a friendly manner) and almost as effectively, to communicate an offence to someone!
(Friendly) John sees his friend Mark approaching. The two haven't met in ages.
John: 'Hey trobas!!!!
:) We haven't met in ages! How have you been malaka
(Hostility) John was mistaken and the person approaching wasn't in fact his friend Mark.
Approaching Person (in response to John's warm greeting): 'Ah Trobas
what are you blind! Go see an optician!'