100 Best Synonyms for “Challenging”

No.	Item	Definition
1.	advanced	Difficult because beyond basic level.
2.	ambiguous	Difficult because open to meanings.
3.	ambitious	Difficult because aiming high.
4.	arduous	Very difficult and tiring.
5.	austere	Strict and difficult to endure.
6.	awkward	Difficult to handle smoothly.
7.	baffling	Very confusing and difficult to explain.
8.	bewildering	Confusing and hard to follow.
9.	brutal	Extremely hard or unpleasant.
10.	burdensome	Difficult because of heavy responsibility.
11.	complex	Not simple; difficult to understand.
12.	complicated	Difficult because of many parts.
13.	confusing	Difficult to understand clearly.
14.	contentious	Difficult because causing disagreement.
15.	controversial	Difficult because people strongly disagree.
16.	critical	Difficult and highly important.
17.	cumbersome	Awkward and difficult to handle.
18.	daunting	Intimidatingly difficult.
19.	debatable	Difficult because not clearly settled.
20.	delicate	Difficult because needing careful handling.
21.	demanding	Requiring great effort or attention.
22.	dicey	Uncertain, risky, and difficult.
23.	difficult	Hard to do or handle.
24.	draining	Taking much energy or spirit.
25.	enigmatic	Mysterious and difficult to interpret.
26.	exacting	Requiring careful effort and precision.
27.	exhausting	Very tiring and difficult.
28.	fatiguing	Causing tiredness through effort.
29.	fiddly	Difficult because needing careful small movements.
30.	finicky	Difficult because requiring exact care.
31.	formidable	Impressively difficult to overcome.
32.	fraught	Filled with difficulty or risk.
33.	grueling	Extremely tiring and difficult.
34.	gruelling	Extremely tiring and difficult.
35.	hairy	Informally difficult or risky.
36.	hard	Requiring much effort or skill.
37.	hardgoing	Difficult and slow to deal with.
38.	harsh	Difficult, unpleasant, and unforgiving.
39.	hazardous	Difficult because dangerous.
40.	heavy	Difficult, serious, or burdensome.
41.	high-pressure	Involving intense demands or stress.
42.	high-stakes	Difficult because much depends on it.
43.	iffy	Uncertain and difficult to rely on.
44.	impenetrable	Extremely difficult to understand or enter.
45.	inscrutable	Very difficult to understand.
46.	intimidating	Frightening because of difficulty.
47.	intricate	Detailed and difficult to understand.
48.	involved	Complicated and hard to follow.
49.	knotted	Complicated and hard to untangle.
50.	knotty	Complicated and difficult to solve.
51.	laborious	Requiring long, hard work.
52.	loaded	Difficult because emotionally or politically sensitive.
53.	make-or-break	Crucial and difficult to face.
54.	messy	Complicated and difficult to resolve.
55.	murky	Unclear and difficult to understand.
56.	mystifying	Difficult to understand or explain.
57.	nuanced	Difficult because of subtle differences.
58.	obdurate	Stubborn and difficult to influence.
59.	obscure	Not clear; difficult to understand.
60.	onerous	Burdensome and hard to manage.
61.	opaque	Difficult to understand or interpret.
62.	oppressive	Difficult because burdensome or overwhelming.
63.	overwhelming	Too difficult or intense to manage.
64.	painful	Emotionally or physically difficult.
65.	perilous	Dangerous and difficult.
66.	precarious	Uncertain, risky, and difficult.
67.	pressing	Demanding immediate attention or action.
68.	problem-filled	Full of difficulties or obstacles.
69.	problematic	Difficult and causing problems.
70.	punishing	Extremely demanding or exhausting.
71.	puzzling	Difficult to understand or solve.
72.	relentless	Continuing with difficult intensity.
73.	resistant	Difficult to change or overcome.
74.	rigorous	Strict, thorough, and difficult.
75.	risky	Difficult because danger is involved.
76.	rough	Difficult, unpleasant, or unsettled.
77.	rugged	Harsh and difficult to cross.
78.	sensitive	Difficult because needing tact or care.
79.	serious	Difficult and deserving careful attention.
80.	severe	Very difficult or harsh.
81.	slippery	Difficult because unstable or elusive.
82.	strenuous	Requiring vigorous effort or exertion.
83.	stressful	Causing pressure, worry, or strain.
84.	taxing	Requiring much mental or physical effort.
85.	testing	Trying one’s abilities or patience.
86.	thorny	Full of difficult problems.
87.	tiring	Requiring effort that causes fatigue.
88.	tough	Difficult to manage or complete.
89.	tricky	Difficult because of hidden complications.
90.	troublesome	Causing difficulty or annoyance.
91.	trying	Difficult and frustrating to endure.
92.	uncertain	Difficult because outcomes are unclear.
93.	uncomfortable	Difficult or unpleasant to experience.
94.	unmanageable	Too difficult to control or handle.
95.	unpleasant	Difficult in an disagreeable way.
96.	unwieldy	Difficult to manage because large.
97.	uphill	Difficult and requiring sustained effort.
98.	wearing	Tiring through continued difficulty.
99.	wearisome	Tiring and difficult to endure.
100.	weighty	Important and difficult to handle.