strengthening, a. invigorating, roborant, [tonic], fortifying.
strenuous, a. [zealous], [ardent], [valiant], intrepid, [vigorous], [active], [energetic].
strenuousness, n. [zeal], [ardor], intrepidity, [earnestness], strenuosity, [activity], [energy].
stress, n. [urgency], pressure; [emphasis], [accent]; [severity], inclemency; [significance], [importance].
stretch, v. [extend], elongate, [lengthen], [spread]; [overstate], [exaggerate]; distend.
stretcher, n. [litter].
stretching, n. tension, distension, [extension], porrection, pandiculation, intension.
strict, a. [rigorous], [stringent], [exacting], [rigid]. Antonyms: [lax], [remiss], [indulgent].
stricture, n. animadversion, [criticism]; [contraction].
strife, n. [conflict], [struggle], [contention], emulation, [competition], [battle].