Synonyms and related words :
abiding, arrogant, assiduous, assured, balanced, calm, cocksure, confident, constant, continuing, convinced, cool, coolheaded, decided, determined, diligent, dogged, enduring, faithful, fast, fiducial, firm, firm as Gibraltar, fixed, hubristic, immutable, imperturbable, in equilibrium, inalterable, indefatigable, indomitable, industrious, inexcitable, insistent, invincible, lasting, loyal, nerveless, never-failing, never-tiring, obstinate, overconfident, oversure, overweening, patient, patient as Job, permanent, perseverant, persevering, persistent, persisting, persuaded, pertinacious, plodding, plugging, poised, pompous, positive, predictable, preoccupied, proud, rapt, reassured, relaxed, relentless, reliable, resolute, rock-steady, secure, sedulous, self-assured, self-confident, self-important, self-reliant, single-minded, sleepless, slogging, solid, sound, stable, steadfast, steady, steady-handed, steady-nerved, steel-nerved, strong-nerved, stubborn, substantial, sure, tenacious, tireless, unabating, unafraid, unblenching, unblinking, unconquerable, undaunted, undiscouraged, undoubting, undrooping, unfailing, unfaltering, unflagging, unflappable, unflinching, unhesitating, unintermitting, uninterrupted, unnervous, unnodding, unqualified, unquivering, unrelaxing, unrelenting, unremitting, unshakable, unshaken, unshaky, unshrinking, unsleeping, unstrained, unswerving, untiring, untremulous, unwearied, unwearying, unwinking, utterly attentive, weariless, well-balanced, without a tremor, without nerves