thy·​rid·​i·​um | \ -dēəm\
plural thyridia\ -​ēə \

Definition of thyridium

1 : a pale spot in the wing vein of some insects especially of the orders Hymenoptera and Trichoptera
2 : one of a pair of oval pits on the second abdominal tergite of some hymenopterans

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History and Etymology for thyridium

New Latin, from Greek thyridion window, diminutive of thyra door

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