n.

1. （應酬話等的）慣用語句，客套話[C]
   "How do you do?" is a polite formula.

   "您好。"是客氣的套語。

2. 慣例，常規；準則，方案[C][（+for）]
   A formula for settling the border dispute has been worked out.

   已擬定一個解決邊界糾紛的方案。

3. 配方，處方[C][（+for）]
   The formula of the medicine is still a secret.

   此藥的配方仍是祕密。

4. 【數】公式；方程式[C][（+for）]
5. 【化】分子式[C][（+for）]
6. 【美】配製成的嬰兒奶粉或奶水[U]
   If you are not planning on breastfeeding, you have to decide on a formula.

   如果你不打算餵母奶，那麼你得決定選一種嬰兒奶粉（水）。

n.

1. (pl. formulae /-liː/ )
   a mathematical relationship or rule expressed in symbols.
   ▸ (also chemical formula) a set of chemical symbols showing the elements present in a compound and their relative proportions.
2. (pl. formulas)
   a method or procedure for achieving something.
   ▸a list of ingredients with which something is made.
   ▸ (also formula milk) a baby's liquid food based on cow's milk or soya protein.
3. (pl. formulas)
   a fixed form of words, especially one used in particular contexts or as a conventional usage.
   ▸a rule or style mechanically followed.
4. (usually followed by a numeral) a classification of racing car, especially by the engine capacity.