'margin call' definitions:

Definition of 'margin call'

From: WordNet
noun
A demand by a broker that a customer deposit enough to bring his margin up to the minimum requirement [syn: margin call, call]

Definition of 'margin call'

From: GCIDE
  • margin call \margin call\ n. (Stock market) A demand by a broker that a customer deposit enough to bring his margin up to the minimum requirement; -- caused by the decline in market prices of a security or commodity purchased on margin[5].
  • Syn: call. [WordNet 1.5]