The word "三朋四友" is formed by directly combining the numeral "三" (three) with "朋" (friend) and the numeral "四" (four) with "友" (friend), creating two parallel units that together function as a fixed phrase. The numerals are used not for precise counting but to convey a sense of numerousness, while both "朋" and "友" synonymously refer to friends, resulting in a compound that collectively means a large group of acquaintances.