Uncritical learner in tricky situation (5)
I believe the answer is:
blind
'uncritical' is the definition.
(as in blind obedience, for example)
'learner in tricky situation' is the wordplay.
'learner' becomes 'l'.
'in' indicates putting letters inside.
'tricky situation' becomes 'bind'.
'l' going within 'bind' is 'BLIND'.
(Other definitions for blind that I've seen before include "Sightless" , "without a way out" , "Like a bat" , "Window screen on a roller" , "cover-up" .)