Synonyms and related words :
absolute, acceptable, agreeable, beyond all praise, certain, chaste, close, constant, correct, defectless, delicate, dependable, direct, effective, efficacious, efficient, even, exact, express, faithful, faultless, fine, flawless, foolproof, handy, helpful, ideal, immaculate, impeccable, indefectible, indefective, inerrable, inerrant, irreproachable, just right, mathematical, micrometrically precise, microscopic, nice, oracular, peerless, perfect, pinpoint, precise, pure, refined, reliable, religious, religiously exact, rigid, rigorous, satisfactory, satisfying, scientific, scientifically exact, secure, severe, sinless, spotless, square, stainless, strict, subtle, sure, surefire, taintless, unadulterated, unblemished, uncontaminated, undeceivable, undeviating, unerring, unfailing, unfaultable, unmistaken, unmixed, unspotted, untainted, useful