third order

Short definition from Wiktionary

Noun

1. 1
   Lay members of Christian religious orders, who do not necessarily live in a religious community such as a monastery or a nunnery, and yet can claim to wear the religious habit and participate in the good works of a great order.

Adjective

1. 1
   Of or pertaining to third-order Greeks, used by portfolio managers and derivative traders to measure risk and the sensitivity of an option in regard to changes in implied volatility, time premium decay, and the price of its underlying security.