A mackeral is a word used in London and the surrounding countys to describe a wannabe gangsta. These are people who try to intimidate others by threatening them with gangster actions such as 'spraying them wiv their Ak's' or 'merking them with their mandem'. However, any attempt to do so would be futlye. The perpertrators are normally 'wastemanz' or 'hairdressers' who try to make themselves feel better by trying to act cool and hard.
Martyn: oi blud , call up yo' Peter Pandem, we gots bare beef wiv rob da hairdresser
Matt: aaww Allow bruv, that bredrin is a Mackeral. I slew manz like dat on da reg just fo jizzlez.
Mackerbate is to masturbate and jizz on your partner's gee while they are sleeping, after which you go to the local shop. Then when you come back with the breakfast and your partner wakes up, they're morto because they think that they're after having a dirty wet dream!
A gasous odor omitting from either a human or dog's anus that combines the smell of typical anal glands, with the raunchous smell of a bloody mackeral laid out for days in the back of a boat.
Damn, have you been by Merle's office recently? Makes me want to puke on a mackeral every time I walk by. That guy is laying mackeral farts downleft and right.