inflexible + -ly
inflexibly (comparative more inflexibly, superlative most inflexibly)
You can also try words with the phrase INFLEXIBLY, words starting with the letters INFLEXIBLY, or words ending in the letters INFLEXIBLY.
Words… ending with q, starting with q, starting with qa, starting with qo, with two letters, starting with x, starting with j, ending with j,
Some random searches:
BKCRWA, JSQU, GUSW, OSOQADO, IOLXCBU, LCZMKO,