The words of the day are.....8 words.
The prefix is "a"="on"
aback 後ろへ I was taken aback by the news. （そのニュースに驚いた）（ニュアンスとしては、take aback でなんか面食らった的な感じ）
abed = in bed He is ill abed （彼は病気で寝込んでいる）
ablaze = on fire 燃えたっている The house was ablaze. The sky was ablaze with fireworks.
aboard = on board 船に 汽車に I went aboard to the island. （島まで乗船した）
afloat = 浮かんで A rumor get afloat.
afoot = 進行中である 徒歩で I went afoot, The plans are afoot.
aground = on ground a ship aground on the rocks 座礁した船
aloof = on loof He stands aloof from others （他人から距離を置いている）
THere are many Prefix "a" and meanings, but it is not that difficult compared to what I expectd.
I think learning little by little is the key to retain vocaburary and knowledge, so I keep on doing every day....