1politeness(in form of address) most trustworthy, very reliable:
(
1324
)
Trescher sire et tresfiable ami
79
(
s.xiv2;
MS: c.1400
)
Mon treshonouré frere et treschere sire et tresfiable amy
41.274
(
1390-1412;
MS: s.xv1
)
Treschier et tresfiable amy
129.77.1
(
1410-15
)
Reverent sire et tresfiable uncle
426.91b
tresfiable (1324)