difficult, challenging
The word abstruse means difficult to understand. A good sentences would be, the toddler was so abstruse that it made us laugh.
Difficult: more difficult most difficult
Fussy means difficult to please.
The state of being complex; intricacy; entanglement., That which is complex; intricacy; complication.
the scientific word that means difficult swallowing is " Dysphagia " ..
'Intractable' means difficult to manipulate, or hard to manage.
Aphasia
The word uneasy means not easy. The word easy means not hard.
The word that means difficult to get along with is "abrasive." It describes someone who is harsh or unpleasant in personality, making it challenging to interact with them.
Hamper
not often means seldom
Endure is the word. It means suffer (something painful or difficult) patiently.
Resolve means to work out a problem.
The word you're looking for is "rugged." It describes terrain that is rough, uneven, and difficult to navigate.
The word "operate" is formed from a base word that means to work or to keep in action.
Crackjaw means a word or a phrase that is difficult to pronounce.