IPA: //ʌnˈdɛviˌeɪtɪŋli//
KK: /ʌnˈdɛviˌeɪtɪŋli/
In a way that does not change or vary; consistently and without deviation.
She followed the plan undeviatingly, ensuring everything went as intended.
Undeviatingly → It is formed from "un-" (meaning not), "deviate" (from Latin "deviatus", meaning to turn aside), and "-ingly" (a suffix forming adverbs). The word means not turning aside or straying from a path, thus indicating consistency or steadfastness.
Think of 'not' ('un-') turning aside ('deviate') from a path, which helps you remember that 'undeviatingly' means to stay on course without straying.