A buffoon or imbecile.
A road vehicle (often a trailer) for the transport of liquid fuel, particularly aviation fuel at an airfield.
A fuel metering/delivery pump at a filling station.
A mobile water tank deployed to distribute fresh water in emergency situations where the normal system of piped distribution has broken down or is insufficient.
Someone who pretends to be knowledgeable on some subject.
Someone who is frequently drunk (pissed).
Someone who frequently ridicules others (takes the piss).