Synonyms and related words :
abiding, calm, constant, coolheaded, failing, firm, fixed, flinty, going strong, immovable, in full force, in full swing, inexcitable, inflexible, loyal, nerveless, never, relaxed, rock-steady, set, settled, sot, staunch, steadfast, steady, steady-handed, steady-nerved, steel-nerved, steely, strong-nerved, TRUE, unabated, unallayed, unbated, unbending, unblenching, unblinking, undeflectable, undiminished, unexhausted, unfaded, unfaltering, unflagging, unflappable, unflinching, unnervous, unquestioning, unquivering, unshaky, unshrinking, unstrained, unswerving, untremulous, unwavering, unweakened, unweakening, unwithered, unworn, unyielding, without a tremor