It is burdensome.
The adjective form of burden is burdened. I traveled with a heavily burdened cart. (Burdened is, of course, a past participle of the verb to burden, but past participles can also be used as adjectives.)
Burdened
The noun form for the adjective difficult is difficulty.
The adjective form of concept is conceptual.The adjective form of conception is conceptional.
The adjective form for the pronoun they is their.
The Adjective form of Pathologist is Pathological.
The adjective form of concept is conceptual.The adjective form of conception is conceptional.
The adjective form of improve is "improved."
No, it is not. The word "rid" is a verb, meaning to relieve (oneself) or a problem or burden.
adjective form of pass.
The adjective form is decisive.