Synonyms of challenging

1 Syllable

tax, cross, claim, dare, beard, test, try

2 Syllables

defy, query, accost, confront, brave, assert, upstream, demand, hard-won, impugn, exact, reclaim, defiant, summon, impeach

3 Syllables

require, provoke, inquire, renewing, arouse, denounce, innerving, difficult, ballbuster, impose, roborant, quickening

4 Syllables

vitalizing, difficile, vindicate, stimulating, stimulate

5 Syllables

reinvigorating, adrenalizing, investigate, inquisitive, provocative