undertook solemnly (verb) vow: make a solemn promise
Sinonime: affirm,
assure,
consecrate,
covenant, cross one's heart,
declare,
dedicate,
devote, give word of honor,
pledge,
plight,
promise,
swear, swear up and down,
testify, undertake solemnly, vouch,
warrantAntonime: disavow