An auction signal is a set of gestures or verbal cues used to indicate bids in an auction. The most common signals are 'NOD' (3 letters), which is a gesture of the head indicating agreement, 'BID' (3 letters), which is a verbal offer to buy something, 'NODS' (4 letters), which is the plural form of 'NOD', 'EER' (3 letters), which is a sound made to express surprise or hesitation, 'EBAY' (4 letters), which is an online auction website, and 'LOT' (3 letters), which is a group of items being sold together.