unconscionable
Concise Oxford English Dictionary © 2008 Oxford University Press:
unconscionable /ʌnˈkɒnʃ(ə)nəb(ə)l/
▶adjective not right or reasonable.
■ unreasonably excessive: they had to wait an unconscionable time.
– derivatives
unconscionably adverb.
unconscionably adverb.
'unconscionable' also found in these Oxford entries:

