soothfast adjective 2adverb 1 adjective2 •(no longer used) Actual; real.So she brought him the China bowl saying in herself, “I shall know what to do when I find out if the words of my child concerning these jewels be soothfast or not”; […] — 2012 •(no longer used) Based on the truth, true; faithful; honest, veraciousWhy do not you […] bear leal and soothfast evidence in her behalf, as ye may with a clear conscience? — 1818 adverb1 •(no longer used) Actually; truthfully.I care not if the pomps you show / Be what they soothfast appear, / Or if yon realms in sunset glow / Be bubbles of the atmosphere. — 1867