Medical Dictionary
2 ENTRIES FOUND:

1challenge

vt chal·lenge \ˈchal-ənj\
chal·lengedchal·leng·ing

Definition of CHALLENGE

:  to administer a physiological and especially an immunologic challenge to (an organism or cell)
March 29, 2015
discomfit Hear it
To thwart or disconcert
Take a 3-minute break and test your skills!
How to use a word that (literally) drives some people nuts.
Test your vocab with our fun, fast game
Ailurophobia, and 9 other unusual fears