The 32-year-old was previously on the books of Scottish side Hibernian FC, from 2016 to the end of last season.
He’s previously played in countries such as Portugal, Spain and New Zealand.
During his time in New Zealand, Moreira netted six times in as many games as Auckland City won the 2017 OFC Champions League.
Arrows, meanwhile, have re-signed Siyanda Zwane from Mamelodi Sundowns on a season-long loan.
Zwane, who was last loaned to Ajax Cape Town in the second half of last season, joined Sundowns from Arrows in 2014 along with Bongi Ntuli, who is set to make a move to Europe.
The 33-year-old Zwane, who has won everything on offer domestically, played 132 games for the Durban-based side and was part of the Abafana Bes’thende team that won the MTN8 in 2009.
Zwane is the second signing for the club following the acquisition of former Chicken Inn left-back Divine Lunga.