Hit the bid
The phrase ‘hit the bid’ refers to the bid-ask spread, the price difference between the highest price a buyer is willing to purchase a security at and the lowest price the holder of that security is willing to sell at. A trader willing to sell immediately at the given bid price will ‘hit the bid.’
Hit the bid vs lift the offer
‘Lift the offer’ is the inverse command to ‘hit the bid,’ and is a command to purchase a security at the given ask price. In this case a trader is ‘lifting’ the offer from a broker. When a trader lifts the offer, they immediately execute a buy at the given ask price.