difficult
dif-fi-cult
adjective
Requiring much effort, skill, or determination; not easy to do or understand.
"The exam questions were extremely difficult."
Thesaurus
Synonyms: uncontrollable, indocile, unruly, uncheckable, unmanageable, ungovernable, incorrigible, rocky, fractious, catchy, unenviable, touchy
Antonyms: easy, manageable