常識
じょうしき · joushiki · JLPT N3 · noun
common sense
常識 = usual (常) + knowledge (識): what everyone ordinarily knows
常 means usual or constant, as in 日常 (everyday). 識 means knowing, as in 知識 (knowledge). Put together: the knowledge that is always there, i.e. common sense. Sound hook: joushiki = the JOe-SHCHIcKY basics every Joe knows.
常 — 巾 (cloth) + 尚 (phonetic, 'esteem')
Originally written 裳, 常 was a phono-semantic compound: 巾 ('cloth') gave the meaning and 尚 supplied the sound, referring to a long lower garment or skirt. Over time the meaning shifted from 'everyday garment' to 'ordinary, regular, constant', while 裳 took over the original clothing sense.