excess baggage       
noun [ U ] uk/ɪkˌses ˈbæɡ.ɪdʒ/ us/ɪkˌses ˈbæɡ.ɪdʒ/ (UK also excess luggage)
 (要缴纳运费的)超重行李
bags that weigh more than the allowed amount for a single passenger, or the money you are charged to take them onto an aircraft
  We had to pay excess baggage. 我们行李超重了,不得不另付费。 
 He arrived with 88 pounds of excess baggage. 他到达时带的行李超重了88磅。