adjective
1. : facing in opposite directions and often touching
standing in a row back to back
train seats back to back
2. : dealt one in the hole and one face up — used of a pair in stud poker
aces back to back
3. : one after the other : consecutive
two home runs back to back in the third inning
back to back telecasts
4. of a letter of credit : granted by a bank to an exporter to finance purchase of goods already covered by a letter of credit in his favor taken out by the importer