demanding β A demanding job or task requires a lot of your time, energy, or attention.
challenging β A challenging task or job requires great effort and determination.
rigorous β characterized by rigor; rigidly severe or harsh, as people, rules, or discipline: rigorous laws.
thorough β executed without negligence or omissions: a thorough search.
testing β the means by which the presence, quality, or genuineness of anything is determined; a means of trial.
tough β strong and durable; not easily broken or cut.
onerous β burdensome, oppressive, or troublesome; causing hardship: onerous duties.
harsh β ungentle and unpleasant in action or effect: harsh treatment; harsh manners.
imperious β domineering in a haughty manner; dictatorial; overbearing: an imperious manner; an imperious person.
painstaking β taking or characterized by taking pains or trouble; expending or showing diligent care and effort; careful: a painstaking craftsman; painstaking research.
precise β definitely or strictly stated, defined, or fixed: precise directions.
rigid β stiff or unyielding; not pliant or flexible; hard: a rigid strip of metal.
strict β characterized by or acting in close conformity to requirements or principles: a strict observance of rituals.
stringent β rigorously binding or exacting; strict; severe: stringent laws.
taxing β wearingly burdensome: the day-to-day, taxing duties of a supervisor.
trying β extremely annoying, difficult, or the like; straining one's patience and goodwill to the limit: a trying day; a trying experience.
burdensome β If you describe something as burdensome, you mean it is worrying or hard to deal with.
by the book β according to the rules; in the prescribed or usual way
careful β If you are careful, you give serious attention to what you are doing, in order to avoid harm, damage, or mistakes. If you are careful to do something, you make sure that you do it.
critical β If a person is critical or in a critical condition in hospital, they are seriously ill.
difficult β not easily or readily done; requiring much labor, skill, or planning to be performed successfully; hard: a difficult job.
finicky β excessively particular or fastidious; difficult to please; fussy.
fussy β excessively busy with trifles; anxious or particular about petty details.
grievous β causing grief or great sorrow: grievous news.
hard β not soft; solid and firm to the touch; unyielding to pressure and impenetrable or almost impenetrable.
hypercritical β excessively or meticulously critical; overcritical.
nit-picking β to be excessively concerned with or critical of inconsequential details.
oppressive β burdensome, unjustly harsh, or tyrannical: an oppressive king; oppressive laws.
particular β of or relating to a single or specific person, thing, group, class, occasion, etc., rather than to others or all; special rather than general: one's particular interests in books.
