以降
いこう · ikou · JLPT N2 · noun
on and after
📅 以 from + 降 go down = from this point on, down the timeline
降 means descend, so 以降 is everything that comes down the calendar after a given point: 明日以降 = tomorrow onward. It is pronounced exactly like 行こう, let's go, so think of it as: from here on, let's go.
以 — phonetic 㠯 (plow/tool) + 人 (person)
Originally a pictograph of a hand-held plow or tool (㠯), later combined with 人 (person) to suggest 'using' something. The core meaning 'to use' extended metaphorically to 'by means of', 'with', and 'because of'. In modern Chinese it functions mainly as a grammatical particle.
降 — 阜 (mound) 阝+ 夅 (descend, phonetic)
Originally depicted two feet (夅) walking down from a mound or hill (阜), showing the act of descending. The 阝on the left is the 'mound' radical, while 夅 carries both phonetic and semantic weight, suggesting downward movement. Pronounced jiàng for 'descend' and xiáng for 'surrender'.