ˈtrothful,a.arch.rare. [f. troth n. + -ful.] Full of ‘troth’ or loyalty, faithful, trusty; trustworthy, truthful. a1380Minor Poems fr. Vernon MS. xxviii. 9 Heil trewe, trouþeful and tretable.1861Lytton & Fane Tannhäuser 13 Trothful men..Aver he was the fairest-favour'd knight.