[dd]
The origins of this word are obscure and may be related to the English word trust (as noted in Romania, 80:317 (1959) p. 117), which the form traistre in Rom de Rou wace tends to confirm (see MED traist(e n. and OED traist n.). It is unclear whether the Anglo-Norman word derives from Middle English tristre or if the reverse is true (see Etymology in OED tristre n.).