(adj-i) intolerable
unbearable
(adj-i) unapprovable
(adj-i) hard to understand
incomprehensible
unintelligible
(adj-i) dignified
(adj-i) unforgettable
memorable
(n) unable to decline
(n) difficult to translate
(adj-i) grateful
thankful
welcome
appreciated
evoking gratitude
(P)
(adj-i) uncontrollable
irrepressible
(adj-i) scratch-resistant
(adj-i) scratch-resistant
(adj-i) hard to imagine
(n) unshakable
immovable
undeniable
(n) illegible
(n) formidable enemy
(adj-i) inseparable
(oK) (adj-i) hard to understand
incomprehensible
unintelligible
(exp) it is difficult to say which of the two is better
(n) awkward (difficult) question
(exp) hard to please
difficult to get on the right side of
(n) impenetrably difficult
(n) impenetrably difficult
(n) beyond description