малОй (capital letter marks stress) - a former nominalised (substantivised) adjective. A noun. Малой is explained by Ася мАлый. 1. noun. means 'guy', 'man', especialy in some expressions: славный малый. Now one may easily find it in books in written form - but rarely in modern speech:) 2. Adjective 'little, lesser". In the sense of 'little, small' was mainly substituted with the form with diminutive suffixes: маленький. созвездия Малая Медведица и Большая Медведица (constellations Ursa Minor and Major) But it is still used extensively in technics etc., where one has a pair of similar objects, a lesser one and a great one. Ex.: "Малый русско-китайский словарь" (supposedly, the publisher prints "Большой словарь" as well, the name 'Малый' stans for 'concise' here) If you are an engineer, and you have invented a machine with "lesser regulator" and 'bigger regulator' in it - you'll surely call them 'малый регулятор' и "большой регулятор":) мАленький. Diminutive suffixed form that has mainly substituted old "малый"

We use "малой" only in colloquial speech when we tell about younger child (brother, son). It is like "kid", "kiddy". And "маленький" is "маленький" (little, small, young).