Romelu Lukaku also scored a hat-trick as the Belgians remained in the group's driving seat with 19 points from seven games, six more than second-placed Greece who were held to a 0-0 home draw by Estonia.
Belgium's victory matched their biggest competitive margin -- a 10-1 mauling of San Marino in a 2002 World Cup qualifier.
And they might have made history but for a moment of madness from their midfielder Axel Witsel, who was sent off for a wild lunge on San Marino's Jamie Bosio near the centre circle after scoring the game's most spectacular goal.
Witsel netted the home side's fourth in the 27th minute with an acrobatic overhead kick after a pinpoint cross by the outstanding Meunier, but 14 minutes later he received his marching orders from Irish referee Neil Doyle.
Apart from making his team mates do his work in the second half, Witsel is certain to pick up a suspension and miss Belgium's next qualifier away to Greece.
Visiting goalkeeper Deren Ibrahim made several good saves eary on as Belgium predictably besieged Gibraltar's goal, but the floodgates opened after he spilled a tame Dries Mertens cross through his legs and the ball trickled over the line.
The hosts were 6-0 up at halftime, with Lukaku bagging two goals and Eden Hazard, who made his first competitive start of the season after shaking off an ankle injury, also scoring.
Although outnumbered on the pitch, Belgium rarely let the visitors out of their own half and missed a string of chances either side of Meunier's double, which made the score 8-0.
A record-breaking win seemed to be on the cards after Lukaku scored an 84th-minute penalty, with Gibraltar defender Erin Barnett sent off for a professional foul, but the home side missed another pair of sitters in the closing stages.
(Writing by Zoran Milosavljevic; Editing by Neville Dalton)
