The Oxford Thesaurus An A-Z Dictionary of Synonyms INTRO ...

ackbone, stamina, tenacity, tenaciousness, will-power,
perseverance, persistence, resoluteness, resolution,
pertinacity, nerve, grit, pluck, determination, gameness,
intrepidity, firmness, stability, Colloq guts, gutsiness, spunk,
US intestinal fortitude, stick-to-it-iveness: Sally was a tower
of strength when I needed her the most. 3 talent, ability,
aptitude, gift, strong point, asset: One of his strengths is
being able to sight-read music. 4 concentration,
concentratedness, intensity, potency: Coffee of that strength
would keep me awake all night. 5 vigour, force, energy, power,
potency, intensity: The strength of the wind was great enough
to pick up cars and toss them about. 6 durability, power,
toughness, stability, reliability, resistance, solidity,
stamina, ruggedness, endurance, soundness: The manufacturer
claims that his product has the strength to resist wear for a
hundred years. 7 persuasiveness, cogency, weight, force,
convincingness, incisiveness, soundness: There is no disputing
the strength of the argument against smoking.
strengthen
v. 1 reinforce, renew, bolster, fortify, support, confirm,
corroborate, substantiate, buttress, step up, boost: A thousand
troops were sent to strengthen the garrison at Fort Old. 2
encourage, hearten, invigorate, fortify, rejuvenate, nourish,
energize, vitalize, toughen, brace (up), steel, innervate,
stiffen: Whatever she said seems to have strengthened his
determination to succeed.
strenuous adj. 1 demanding, taxing, tough, arduous, laborious, toilsome,
burdensome, tiring, exhausting, difficult, hard, uphill:
Hauling in the fishing nets was strenuous work. 2 energetic,
active, vigorous, enthusiastic, zealous, earnest, dynamic,
intense, indefatigable, tireless, persistent, dogged,
determined, tenacious, pertinacious, resolute, sincere, eager:
He has made a strenuous effort to be more accommodating.
stress n. 1 emphasis, force, pressure, forcefulness, accent,
accentuation, prominence, Technical ictus: Many people place
the stress on the first syllable of 'controversy'. 2 emphasis,
significance, importance, weight, force, insistence, urgency:
She lays too much stress on looks. 3 (stress and) strain,
burden, anxiety, worry, distress, pain, grief, suffering,
anguish, pressure, tenseness, tension: She has four elderly