An order to deal at a specific rate o better.
An instruction to trade at a given level or better.
In connection with a buy order, it means to purchase at the price specified or under; in a sell order, to sell at the price specified above.
In connection with a brokerage buying order, to purchase at the price specified or under, in a selling order, to sell at the price specified or above
An order to deal at a specific rate/price or better.